PRTG Network Monitor - Version History

New

Sensors

SNMP Custom String v2	With this PRTG version we introduce the new SNMP Custom String v2 sensor that monitors a string returned by a specific object identifier (OID) via the SNMP. The sensor interprets the SNMP value returned by the OID as a string, a MAC address, or an IPv4 address and shows the interpreted value in the sensor message. We introduced this sensor as experimental BETA sensor with PRTG version 26.1.116.1498.
SNMP Printer v2	We added the new SNMP Printer v2 sensor to monitor printer status, consumables, and operational metrics via SNMP. The sensor supports IPv4 and IPv6. Depending on the monitored printer, the sensor creates the channels Total Pages Printed, Cover Status, Tray Status and Supply Status. The sensor message displays the printer console output. If no printers are defined in the device table, the sensor will report an error. This sensor introduces 1-based numbering for printer units, as well as removing ranged lookups in favor of direct percentage and lookup values.
SNMP RMON v2 sensor	With this PRTG version we introduce the new SNMP RMON v2 sensor that was rewritten to work also on the Multi-Platform Probe. The SNMP RMON v2 sensor monitors traffic on a device using the Remote Monitoring (RMON) standard via SNMP. In the Specific Sensor Settings you have the option to edit the settings Description or 64-bit on request. This information is collected during sensor creation and if 64-bit counters are enabled in the compatibility settings.

New

Server

Reports

With this PRTG version we introduce the PRTG Installation Report, a new built-in report available by default in all standard PRTG installations under Reports menu. With this report you can collect data about your PRTG installation, including license information, system health and optimization recommendations. The report can be generated on-demand or scheduled for automated delivery. The report supports PDF, CSV and HTML formats.

Improved

Security

Webserver

We performed sanitization on HTTP error responses to prevent information disclosure.
We performed sanitization on the URL Path in HTTP error responses to prevent information disclosure.
We enforced input sanitization on object name parameters to defend against possible Cross-Site Scripting.
We hardened PRTG against possible cross-site scripting attacks through certain parameters on the public login page.

Improved

Sensors

Microsoft 365 Mailbox sensor

The Microsoft 365 Mailbox sensor now supports the setting Validate Latest Email, like for example, the IMAP sensor. The sensor will use the latest email from the filtered messages. If no filters are configured, all messages are taken into account. You can configure warning or error states based on the Subject, From or Body settings. Additionally, you can set the sensor to Down or Warning status based on age for the latest email.

Changed

Server

Activated PRTG Database (BETA)

In case of a manual update to this PRTG version and if you have previously activated the PRTG Database, you will see an installation window with the message that the installation has stopped in order to keep your existing data. This is due to a new schema update in this PRTG version. The installation window will provide further instructions on how to proceed with the update.

The auto-update process will currently stop when you update to this PRTG version if you have previously activated the PRTG Database and have existing data. This issue affects you if you have set your auto-update to Automatically download and install in the Software Auto-Update settings. PRTG will create a TO DO ticket Error: The update cannot continue due to a change in the database schema if you run into this issue. For more information, please see our Knowledge Base article: https://helpdesk.paessler.com/en/support/solutions/articles/76000088264

Changed

Sensors

Custom sensors

We updated the list and location of the example scripts for custom sensors in the PRTG program directory. This removes all Demo scripts from the pre populated custom scripts directory. Scripts that were not deemed as risky are preserved under the examples script directory. Additionally, we have updated the example scripts for Script v2 to follow a more modern structure. Please note that in course of this change that we removed any .dll and .exe demo binary from PRTG.

Changed

WebGUI

System Status

To be consistent with our changes in PRTG version 26.1.118.1380 to display information about sensor usage and licensing in the New UI, we removed the Number of Sensors part under License Information on the PRTG System Status page.

Fixed

Server

Geo map	We fixed an issue where in certain cases an enabled Geo Map could lead to ajax timeout errors or slow performance in the PRTG web interface. You could observe this issue when your PRTG core server was blocked in your firewall for outgoing connections and PRTG would try to reach the geolocation service continuously. A possible workaround was to disable Geo maps.
NATS setup	We fixed an issue that occurred when you updated to previous PRTG version 26.1.118.1380 and when you have previously set your local storage of data files and monitoring database folder in the PRTG Administration Tool to root of a drive, e.g. C:\. In this case, you would receive an error The PRTG installation stopped due to a NATS setup error. "NatsManager.exe: Failure during NATS configuration with return code=95". This error was also logged in setup.log, along with an initiated rollback of the version. Despite this, the PRTG Database service continued to run, but without the NATS installation and as a result, PRTG was no longer usable.
PRTG Core service	We fixed an issue where the PRTG core service used a large amount of memory in rare cases which caused the system to run out of memory in the end. You could find the error message out of memory in the core log file in such cases.

Fixed

Sensors

NetApp SnapMirror v2	We fixed an issue for the NetApp SnapMirror v2 sensor which regularly went into an error state and did not return any values for certain channels. The ONTAP API omitted transfer fields for continuously synced relationships and the sensor would handle the missing values as error. The issue happened when you used ONTAP with SnapMirror Active Sync and Consistency Groups.
DNS v2 sensor	We have improved the DNS v2 sensor regarding filtering reliability and result consistency. Null MX records are now correctly displayed as 0 if a domain does not accept emails, and DNS records of the same type are now sorted alphanumerically to ensure consistent output across repeated requests. Record values are trimmed before filter matching to prevent whitespace-related mismatches. A new Match the full result exactly filter mode has been added for record types whose values naturally contain commas, such as TXT and NAPTR. The internal connectivity check now queries the root domain for NS records instead of using a localhost ANY query, improving compatibility with modern DNS servers.
Ping v2 sensor	We fixed an issue where having multiple ping sensors targeting the same host caused all raw ICMP sockets to receive all answers, resulting in an error message Received packet had unexpected identifier or sequence number in the Result of Sensor logfile. The sensor also wrongly reported packet loss in case of packets received with a mismatching type or identifier. You are now able to use a new setting for the Ping v2 sensor Error Status Handling, to define an evaluation method to display negative results. The sensor immediately shows the Down status based on channel lookups for the setting Enter the down status immediately (default).

Fixed

WebGUI

Auto-discovery

We fixed an issue where Run Auto-discovery with Templates led to an error (bad request) when you selected device templates via multi edit. Previously, it was only possible to select device templates on the first page of the pop-up window. As soon as you selected a device template on the second page or beyond, an error message appeared stating no device template had been selected.

Fixed

MultiBoard

API Keys

We fixed an issue for Desktop Client and MultiBoard related API keys that you can create in PRTG via Add API Key for PRTG MultiBoard button. The issue happened when you started the Single Sign-on login flow calling getdesktoptoken.htm. The API key that was returned from the endpoint did not work for Single Sign-on content in those cases.

Note

Known Issues

PRTG Database migration (BETA)

We currently face an issue where it is not possible to log in via Single Sign-on after enabling PRTG Database for data migration. If you have set up Single Sign-on before and migrated your configuration to PRTG database, the login with Single Sign-on would fail afterwards. In the User Group Settings you could observe that the SSO Group Claim was missing. A possible workaround is to set up a new Single Sign-on user group.

PRTG installer

Please note that with updating to this PRTG version, the auto-update process takes longer because it includes the PRTG database and related components, which increase the size of the PRTG installer. We strongly recommend that you do not restart PRTG during this process and wait until the update is complete.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 26.2.120.1449

sha256_exe 62E2681F26E81436A24C2EB0BE26CADEADFD0D529A400FB7DACE806680CCFD83
sha256_zip A1CE8074AD75B4E06E9567A7EDFC27FDE64D5F83364AB21287FE9AEDA7324236

PRTG Database (BETA)

PRTG Database (BETA) components and files will no longer be installed for new PRTG installations or if you update from older PRTG versions to PRTG 26.2.120.1449 or higher. Older PRTG versions in this case are versions prior to PRTG version 26.1.118 which includes the PRTG Database installer. If you want to skip the PRTG Database and are updating from an older version or performing a fresh installation, please update directly to this version 26.2.120.1449.

Lab

Server

PRTG Database (BETA)

We fixed an issue where certificates created by NATS Manager were never deleted from the Windows Certificate Store. The certificates NATS Server for Paessler PRTG and Paessler NATS Manager are now properly removed when PRTG including NATS is fully uninstalled, when an initial installation is canceled or rolled back, or when an update is rolled back to a previous PRTG version without PRTG Database.
With this PRTG version, the PostgreSQL Database installer will no longer install the pgAdmin tool if you have already installed a PRTG version with the PRTG Database. Your installation will proceed as expected, but the pgAdmin tool will no longer be updated in this case.
We fixed an issue where setting up the PostgreSQL database with a custom password failed if the password contained certain special characters. The installer now validates both the username and password against the allowed character sets in real time. The PostgreSQL username is restricted to alphanumeric characters only, while the password additionally allows the following special characters: _ ! . + - = ~. An error message is displayed and the user cannot proceed until invalid characters are removed. The setup screen now also clearly displays these constraints to guide users during configuration.
We fixed an issue when the installation was cancelled in certain cases either manually or due to an error. The PRTG installer will now inform you about the process and the next steps with the message: Roll back of all changes done within this installation finished. Please reboot your system.
We fixed an issue that occurred if you canceled the installation or rolled back to the previous PRTG version. In that case, the PRTG Administration Tool could no longer be started because the .exe file was no longer present.
We fixed an issue that occurred in certain cases if you had PRTG installed with a Multi-Platform Probe connected and updated to a PRTG version that includes the PRTG Database. After updating, the NATS service was stopped and could not be started again. Additionally, the NATS server.log file was not created. In the Windows Event Logs you could find the following error: The service did not respond to the start or control request in a timely fashion.
We have updated our PostgreSQL database from version 18.1 to 18.3.

Data migration

We fixed an issue where sensor tags were lost after migrating configuration and monitoring data to the PRTG database. This caused sensors to become invisible in tag-based filters, making libraries and reports that rely on tag filtering no longer work as expected. This issue applied to the WMI Free Disk Space (Multi Disk) sensor, for example.

Lab

Sensors

SIMATIC S7-300/400 CPU Restart Overview sensor	We improved the retry mechanism for the SIMATIC S7-300/400 CPU Restart Overview sensor to reduce false alerts caused by intermittent errors when querying data from a PLC via S7. Previously, the PLC would occasionally return a CPU : Item not available error, causing the sensor to go into a down state for one or more scans before recovering, despite the PLC working correctly the whole time. When the PLC is too busy to serve the request of the sensor, the request is now retried after a delay of 100 ms, with a configurable maximum delay of up to 1000 ms.
SIMATIC S7-300/400 CPU Status sensor, SIMATIC S7-300/400 CPU Restart Overview sensor	We fixed an issue for the SIMATIC S7-300/400 CPU Status (BETA) and SIMATIC S7-300/400 CPU Restart Overview (BETA) sensor that did not display any data results in certain cases. The issue happened because the sensor did not finish the scan for some monitored PLCs. We fixed an issue for the SIMATIC S7-300/400 CPU Status (BETA) and SIMATIC S7-300/400 CPU Restart Overview (BETA) sensor that reported an error message The buffer supplied is too low to accomplish the operation in certain cases. The issue happened for S7-410-5H controllers when the sensor failed to read the diagnostic buffer.
SNMP Custom String v2 sensor	We added a new setting Numeric Extraction to the Specific Sensor Settings of the SNMP Custom String v2 (BETA) sensor, which allows you to locate numbers inside a string from the SNMP device by using regular expressions. The sensor then displays the result in an additional channel: Extracted Number. We have improved the SNMP Custom String v2 sensor by changing the primary channel from Response Time to String Found. The Response Time channel did not display a meaningful error message if you used too many wildcards in the Search String setting. The primary channel String Found will display The search string contains too many wildcards in this case. Important: To get the new primary channel String Found, you need to create this sensor again.
SNMP Traffic v2	We fixed an issue for the SNMP Traffic v2 sensor that wrongly displayed 4 GBit/s as a result for unconnected ports in certain cases. The issue happened mostly for SNMP version v1 or high speed interface connections. The sensor will now display the status Unknown correctly for non-available entries instead of a wrong value.

Lab

PRTG APIv2

API

With this PRTG version we introduce parameter support for the metascan endpoint /experimental/{id}/metascan to create a NetApp System Health sensor via POST request on /experimental/devices/{id}/sensor. The metascan endpoint now accepts a request body with parameters as defined in the schema, allowing the NetApp System Health sensor metascan to be triggered successfully via URL parameters.
We fixed an issue where consecutive calls to /experimental/schemas/{deviceID} returned inconsistent results for the same sensor. Affected sensors, particularly Dell EMC sensors such as paessler.dellemc.storage_filesystem_v2_sensor and paessler.dellemc.storage_capacity_v2_sensor, could alternately appear as creatable with no hints in one call and non-creatable with a MissingCredentials hint in the next. Consecutive calls to the schema endpoint now consistently return the same results.
We fixed an issue where the PRTG application server responded with a panic.log file including the message panic: runtime error: invalid memory address or nil pointer dereference. The issue occurred when you executed a GET request on endpoint /experimental/schemas/{parent}/post with parent=40 (local probe) and kind=snmpcustomtable.
We fixed an issue where the api/v2/settings/public endpoint did not return the correct language upon GET request. Previously, only en-US was returned for the language field. The endpoint will now correctly display the language you have configured in the PRTG webinterface settings.
We have improved the endpoint /experimental/objects/{id}/clone with better documentation in Swagger UI, for example. The deprecated endpoint clone endpoints experimental/devices/{id}/clone was removed.
We fixed an issue in PRTG API v2 for the endpoint api/v2/channels/{id} where for some channel items the name field was returned with an empty string.
We fixed an issue for the /experimental/schemas/{id}/get endpoint that did not handle the readonly property correctly for Read Only users that have the right to acknowledge alarms.
We renamed the PATCH endpoint to /experimental/sensors/{id} to be consistent with other resource endpoints that use the object plural.
We have updated the endpoints POST /experimental/devices/{id}/sensor and POST /experimental/devices/{id}/metascan in PRTG API v2 to now support all sensor kinds. Previously, only a selected set of fully tested sensors were allowed. With the sensor creation flow working reliably, the whitelist restriction has been removed, making sensor creation available for all supported sensor kinds without limitations.

Lab

New UI

Channel units	We fixed an issue where the Channel Unit Configuration did not display the correct units for Disk size, File size and Memory size.
Device tree	We fixed an issue for the Device Tree in the New UI that displayed an additional Add Sensor button when you entered a search string in the search field. You can now move devices into different groups and reorder objects within a parent in the new UI. Active monitoring objects are now highlighted across the full row width for better visibility, and a context menu has been added to streamline navigation and management actions.
Monitoring	We fixed an issue for the object tree under Monitoring where object calculation did not work properly for groups that contained only empty objects (groups or devices) and no sensors.
Objects	You are now able to use the following Device Action buttons via context menu: Reorder Tree, Copy and Paste. After you have copied an object, a success message appears. The same applies to the object once you have successfully pasted it. If you do not have the necessary access rights to an object, the buttons in the context menu will appear disabled and display the text no permission.
User session	We fixed an issue where in certain cases an unknown error occurred with the message Something went wrong. Please refresh your browser or try again later. The issue in the new UI happened sporadically and in cases when you closed the browser and opened PRTG again with a page using iframes.
PRTG Home page	We improved the Home page in wording and display of content to match the user type that is logged in to PRTG. You are now able to use our new AI Chatbot Max on the Welcome Page in PRTG New UI. Clicking the Start Chatting button opens a slide-in panel on the right side of the page, where you can interact with the chatbot. MAX AI has in-depth knowledge of PRTG and is ready to assist you with questions and troubleshooting directly from the Welcome Page.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German and Spanish language files.

Improved

Security

Authentication

We improved the authentication implementation of PRTG to defend against potential timing attacks and username enumeration.

New

Sensors

SNMP Windows Service v2

With this PRTG version we introduce the new SNMP Windows Service v2 sensor that was rewritten to provide improved reliability and maintainability. This sensor monitors a Windows service via SNMP and uses credentials in Credentials for SNMP Devices that you have to configure in the device settings.

Improved

Sensors

SNMP v3

With this PRTG version we support authNoPriv as Authentication Method for SNMP sensors and SNMP version v3. The authNoPriv mode enables you to monitor infrastructures that only allow authentication without encryption. To use this authentication method, you have to select None as Encryption Type in the credentials for SNMP devices to disable encryption.

Kerberos authentication for WMI sensors

To follow up with the NTLM deprecation process from Microsoft and as a first iteration to support Kerberos for WMI sensors, we have implemented a toggle to use WSMan for WMI connections in the PRTG Administration Tool. In the Probe Settings for Monitoring you will see an additional radio button where you can select Use WSMan for WMI connections, however, DCOM is still activated by default. You can set WSMan for WMI connections for each probe.

In the PRTG settings Credentials for Windows Systems you can select the option Only Kerberos as WMI Authentication Method. To use the Only Kerberos setting, please enable the WSMan protocol on the probe system in the PRTG Administration Tool before. You can also select Negotiate (Kerberos, Fallback to NTLM) in the WMI Authentication Method when WSMan protocol is active. In this case, PRTG will establish a connection using Kerberos authentication.

Changed

WebGUI

License Status

To give you an improved and accurate view of Maintenance Days Left and Sensors Available, we have removed the widget on the page welcome.htm in PRTG and replaced it with a link to the New UI. The button Need Accurate License Details? links you to the New UI which provides a transparent and consistent overview of sensor usage. In course of this, we have removed the Number of Sensors count on the License Status page in the classic web interface.

Important: You have to enable the PRTG API v2 and New UI on the setup.htm page first to be redirected to the new license overview in the New UI.

Fixed

Server

PRTG Administration Tool	We fixed an issue in the PRTG Administration Tool where strings in buttons e.g. were truncated for certain languages. Affected tabs were, for example, PRTG Application Server and NATS Server when you opened the PRTG Administration Tool in German.
Device settings	We fixed an issue in the device settings for Credentials for Microsoft 365 that occurred when you entered an invalid Tenant ID. In this case, you would receive a bad request error message, however, the changes were saved and you were not able to change any other device settings afterwards.

Fixed

Sensors

Folder sensor	We fixed an issue for Folder sensors that occurred when you have monitored network shares that contained certain utf-8 special characters in their file names. In the Result of Sensor logfile you could see the following error message: No mapping for the Unicode character exists in the target multi-byte code page.
Ping v2	We fixed an issue for the Ping v2 sensor where the channel Status was not set as primary channel when you had the setting Inverted Error Status enabled.
Microsoft 365 Mailbox sensor	We fixed an issue for the Microsoft 365 Mailbox sensor when you have selected "...matches regular expression" in the Filter Messages for Subject, Form and Body. The issue occurred in cases when you used an invalid regular expression. The sensor would display an error message that was only partially translated in these cases.
SNMP Disk Free v2	We fixed an issue for the SNMP Disk Free v2 sensor that reported a broken error message and could not read the disk when the disk name contained certain language characters. Any non-conforming character in the disk name is now translated into its hexadecimal representation. Please note that you must recreate the sensor for these changes to take effect.
SSH Disk Free v2	The SSH Disk Free v2 sensor now detects all available filesystems during sensor creation for Linux distributions. Previously, the sensor did not offer and create all available filesystems as channels like its predecessor SSH Disk Free which resulted in missing channels afterwards.

Note

Update Notes

Tree Version Update	The configuration file of this version is not downwards compatible with previous PRTG versions.
PRTG intermediate version 26.1.116.1532	To update to subsequent PRTG versions, you must first install the following PRTG version: 26.1.116.1532 Stable. PRTG 26.1.116.1532 serves as an intermediate version when you want to update from older PRTG versions to subsequent versions. This step is necessary because we had to update our code signing certificates.

Note

Known Issues

Auto-update	This release contains a new code signing certificate and a corresponding intermediate version which will cause the auto-update process to run two times, please be informed that this could lead to longer update times and multiple reboots. Important: If you update your PRTG manually, please note that you need to update to the intermediate version 26.1.116.1532 first before you are able to update to the released PRTG version 26.1.118.1380.
PRTG API v2	We currently face an issue in the PRTG API v2 for the new endpoint /api/v2/oas/objects/move/{id} where moving a sensor within a device to a different position led to an error in the response. The response returned was a 400 bad request HTTP error with the message The request could not be processed.
PRTG installer	Please note that with PRTG version 26.1.118.1380, the auto-update process takes longer because this version and subsequent ones include the PRTG database and related components, which increase the size of the PRTG installer. We strongly recommend that you do not restart PRTG during this process and wait until the update is complete.
Signature	In certain cases, the PRTG core server does not start anymore after updating to PRTG 26.1.118 and the log file core.log contains the message: Signature of \Program Files(x86)\PRTG Network Monitor\32 bit\PRTG Server.exe is not valid or Signature of \Program Files (x86)\PRTG Network Monitor\64 bit\PRTG Server.exe is not valid The issue mainly affects PRTG installations that are offline or have limited access to the internet and happens if the code signing signature fails due to a missing trust chain in the trusted root certificates of the Windows certificate store. You can resolve the issue by adding the trusted root certificate for timestamp signature. For more information, see the Knowledge Base article After updating to PRTG 26.1.118, the PRTG core server does not start anymore.

Note

Installer

Security	You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels: Stable 26.1.118.1380 sha256_exe A8C6E30D0415DC32D67D50887588AED3198F31BCD8258BBB448F7DCB118E2444 sha256_zip F34DDD69CE8F0CA9FC7149E123092AF611E774FB050B604E9B5DF646190C37CD
26.1.118.1381	With this release, version 26.1.118.1381 is also available, as we are currently executing an A/B test. This version will therefore only be displayed for installation if you are in the corresponding group for a PRTG trial installation via website download. Apart from all changes that are included in 26.1.118.1380, this version comes with improvements and new features for our New UI.

Lab

Server

PRTG Database (BETA)

With this PRTG version we introduce PRTG Database, developed for data processing and storage in PRTG as a first Beta release. PRTG Database is designed to increase efficiency and speed, especially in large installations with many sensors and data points. It is an alternative to file system storage and uses PostgreSQL to store raw monitoring and configuration data. The PRTG Database will install files and components automatically when you update to this PRTG version, however, it is currently deactivated by default.

Important:

You cannot activate PRTG Database on a PRTG installation that runs a Cluster setup in this first iteration.
Please note that for the Beta release, you cannot install PRTG core server on a system that already has a database (e.g. PostgreSQL) installed. The installation will fail with an error message in the installer informing you that PRTG requires its own database.
Please note that you have to start the PRTG services manually in certain cases when you run a Cluster setup with PRTG and update to PRTG version 26.x.117. When you have set your PRTG to Automatically download and install in the Auto-Update settings, the installation will run successfully. However, the services remain stopped and must be started manually.

Lab

Sensors

Database Health (Autonomous)	PRTG will create the Database Health (Autonomous) sensor automatically when you update to or install this PRTG version 26.1.117. The sensor is created within the PRTG Core Server group and monitors the PRTG Database service as a first iteration. The sensor will report an error if the PRTG Database service is not running.
Proxmox VE Cluster Health sensor	You can try out the experimental Proxmox VE Cluster Health sensor (BETA) that monitors the health status of Proxmox VE clusters. Available channels for this sensor type are Quorum Reached, Active Nodes, Online Nodes and Total Nodes. To use this sensor type, please enter the Credentials for Proxmox in the device settings with API token authentication. Please note that the channel Ceph Status is optional and is only available when you have configured a Ceph file system before.
Proxmox VE Node Performance sensor	You can try out the Proxmox VE Node Performance sensor that monitors performance metrics and status of Proxmox VE host nodes. To use this sensor type, please enter the Credentials for Proxmox in the device settings with API token authentication.
SIMATIC S7-300/400 CPU Status sensor	We improved the SIMATIC S7-300/400 CPU Status sensor (BETA) which now displays the Maximum OB1 Cycle Time in the Specific Sensors Settings if you have set it before during sensor creation. The Maximum OB1 Cycle Time describes the maximum cycle time for the program cycle organization block (OB1) what PRTG uses to calculate the value of the Cycle Ratio channel.
SIMATIC S7-300/400 LED Status sensor	You can try out the experimental SIMATIC S7-300/400 LED Status sensor (BETA) which displays the status of all physical LEDs on the front panel of a SIMATIC S7-300 or S7-400 controller. The sensor will automatically create one channel per LED that is actually available on that monitored PLC model. Depending on the status of the LED, the sensor displays a message for the respective channel, which is mapped via lookup values. For example, Maintenance Required (MAINT) will show the status OK if the LED has the value OFF.
SNMP Custom String v2 sensor	We improved the search method for the SNMP Custom String v2 sensor for search with wildcards and when you have set Interpret Result As to String (default) in the sensor Settings. The sensor has a new setting Search String Contains with the options Simple string (default), Wildcards and Regular expression. You can replace parts of your substring by wildcards, for example ? matches a single character. You can find the returned value in the channel String Found.
SSL/TLS Security Check sensor	You can try out the experimental SSL/TLS Security Check sensor which is the successor to the SSL Security Check sensor. The SSL/TLS Security Check sensor supports modern protocols to ensure secure encrypted connections. Unlike the old sensor, TLS 1.3 is also supported. TLS 1.2 and TLS 1.3 are set as accepted (default) in the sensor settings Security Evaluation, whereas weaker protocols (SSL 3.0, TLS 1.0, TLS 1.1) are set to denied (default). This sensor type can also be created on the Multi-Platform Probe.

Lab

PRTG APIv2

API

We have expanded our endpoint /experimental/devices/[id}sensor in PRTG API v2 with new supported sensors, which are also listed in the endpoint description and which can be created via POST request. For the SNMP Traffic v2 and Windows Network Card sensor you have to perform a Metascan before on the relevant endpoint /experimental/devices/ID/metascan via POST request in order to create the sensor.
We have improved our endpoints regarding usergroups that only allow certain sensors to be created and when you are logged in to Swagger with a user assigned to such a group. The endpoint /experimental/schemas/{parent} now only returns the selected sensor types from the according group upon GET request. POST request on /experimental/devices/{id}/metascan and /experimental/devices/{id}/sensor with device ID and kind=different sensors will return only the selected sensors in the response.
We fixed an issue for the endpoint /experimental/devices/{id}/autodiscovery when you executed a POST request for autodiscovery with device ID and a body with wrong or not existing discovery-template. In this case, only a generic error message was returned. You will now receive a correct error message: one or more templates could not be found.
We have added a new endpoint /objects/{id}/move where you can execute POST requests in order to move the position of any monitoring object within it's siblings or to a new parent. In the Description section you can enter the ID of the object that you want to move. Additionally, you can combine parameters, for example with the position_preset parameter to move objects to a new parent.
You are now able to create an SSH Disk Free v2 sensor via POST request on the endpoint /experimental/devices/{id}/sensor with the kind ID paessler.ssh.disk_free_sensor. We have also updated the description for supported sensor types for this endpoint in the Open API Specification.
We have expanded the experimental/schemas endpoint so that the response shows whether a sensor can be created or not due to missing credentials. For example, if you execute a GET request on /experimental/schemas/{parent} with according parent ID and limit, you will see for the according credential group either creatable:true or creatable:false for a sensor. In case of creatable:false the flag CredentialsMissing is returned in the response as well.

Lab

New UI

Layout	We fixed an issue where certain pages were displayed for a few seconds in the classic web interface. This issue happened sporadically and the new UI was displayed after automatic or manual refresh of the pages. This issue could affect the Maps and Reports pages, among others.
Monitoring	You can now enter and save notes in the new Comments tab which we have implemented for each monitoring object (Probe, Group, Device, Sensor level). You will receive a success message after saving your changes. Please note that the new Comments tab is not yet available on Mobile view. If you have existing comments in the classic web interface for that object, you will see the comments now also in the new UI.
Sensor channels	We fixed an issue that occurred on the sensor Channel Overview page where unknown errors would be displayed. The issue happened after a certain page refresh interval, that is, after a page refresh you could observe an unknown error message toast.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German and Spanish language files.
Sensors languages	We updated the German and Spanish language files for certain sensor types.

Fixed

Server

Single Sign-on

We fixed an issue for Single Sign-on where it was not possible to log in with a Single Sign-on user when you updated to the previous PRTG Stable version 26.1.116.1498 and when you had Single Sign-on configured for your PRTG. The login failed and the page no longer worked. The error message too many redirects was displayed in those cases. If necessary, you may need to clear your browser cache and cookies.

Note

Installer

Security	You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels: Stable 26.1.116.1532 sha256_exe 5A19643A15A9704C7FDD82DD9B4D9AD8BD4D64E19C1CCB09DCBE44ADEE25AAAD sha256_zip 34EAC4DF0428B30C92000AAEA0E483C6ECDE500EB43AF6F313AA26200B5E8CBF
26.1.116.1535	There is an additional installer build 26.1.116.1535 for select distributions, which contains the same content as build 26.1.116.1532.

Improved

Security

Webserver

We have set the HTTPOnly and SameSite flag for the cookies created by PRTG to strengthen secure transmissions.

Improved

Server

API tokens	We improved the security handling for API tokens regarding interactive web sessions by restricting access for API tokens to certain endpoints.
Single Sign-on	Single Sign-on users are now able to create API keys that can be enabled in the Single Sign-on account settings. As a prerequisite, SSO must be configured in PRTG and an SSO group must exist. You can then enable the new feature Enable API Keys for SSO Users in the Single Sign-on user group settings, which is disabled by default. Additionally, this setting includes a field SSO API Key Lifetime (Days) where you can set the days for how long the API key is valid. When SSO API keys expire after the configured lifetime, the relevant API keys will be cleaned up automatically. As a Single Sign-on user, you can use the SSO API keys also for API authentication.
User account settings	We have implemented a character limit of 240 characters for the Display Name in the User Account Settings. You cannot save changes if the Display Name exceeds the character limit and you will receive an error with the message The display name cannot exceed 240 characters.

Fixed

Server

Logging

We fixed an issue where in certain cases activating an incorrect license key for PRTG Subscription licenses led to access violations in the Core.log file.
We fixed an issue in the Core.log and CoreActivationLog which created incorrect log entries when you changed the license key in your PRTG. This issue only occurred if you had previously changed the log level to DEBUG. After you have changed the license key, you could see a warning message in the Core.log processing of activation data failed. Furthermore, the license activation success message, for example Startup: Error during activation of license PPEM: Activation successful was logged as error.

License activation

We fixed an issue where the License Name was cut off in certain cases on the License Status page when you did use special characters, in this case quotation marks ", in the license name.
We fixed an issue for licenses that could happen when you clicked on the Down sensors on the home page to open the sensors list and tried to delete them via multi edit selection. In this case, you would receive an error object not found for those sensors afterwards. Additionally, you could find errors logged in the Core.log as exceptions. The issue also occurred in PRTG when you have activated it on an offline system.

Fixed

Sensors

Cloud HTTP v2	We fixed an issue for Cloud HTTP v2 sensors that reported the error message The queried field "message" is empty in certain cases. The issue also happened when you monitored different endpoints in various Azure regions.
DNS v2 sensor	Your DNS v2 sensor now only accepts IP addresses that exactly match the value you configured in the filter. The previous version did not allow exact matching of the results, which could cause false positive results. For example, an IP address matching the filter with one digit more was also accepted.
HPE 3PAR Drive Enclosure	We fixed an issue for the HPE 3PAR Drive Enclosure sensor that reported an error with the message Invalid response structure encountered, some data is missing. in certain cases. The sensor log also displayed an invalid showcage command. The issue occurred when you used this sensor type for HPE Primera Storage systems.
HTTP sensors	We fixed an issue for certain HTTP sensors that were missing in the Add sensor list or stopped working in some cases when you updated to a previous PRTG version. This issue has occurred since PRTG version 25.1.104.1946 and affects the following sensors: HTTP Push Data Advanced, HTTP IoT Push Data Advanced and HTTP Data Advanced sensor. In some cases, an error message was logged if you already had HTTP sensors running in PRTG: Could not load "sensor ID: Osk for httppushdataadvanced was not loaded!
File System	We improved the error handling for file system sensors, for example, Dell EMC Unity File System v2 sensor, to better map error messages like The specified network name is no longer available.
OPC UA settings	We removed the deprecated setting Basic256 in the Security Policy section of the Credentials for OPC UA. This setting was deprecated due to the used hash algorithm Sha-1. Please note that your OPC UA sensors will report an error message if you have configured the Basic256 setting and update to this PRTG version.
Sensor channels	We fixed an issue for the scaling factor sensor channel setting where you can enter a multiplication or division scaling factor for sensors with custom units. The issue occurred, when you have configured a scaling factor for your sensor and at the same time entered channel limits. After saving the changes, you could observe that the channel limits were either divided or multiplied with the value you have entered as scaling factor.
SNMP Windows Service sensor	We fixed an issue for the SNMP Windows Service sensor that occurred in certain cases when you have used this sensor type in a device template. For example, when you have configured a device template with the SNMP Windows Service sensor and have set an include/exclude filter for a certain service and run an auto discovery later on a device to create the sensors. When you delete one of those sensors afterwards and run the device template again, the deleted sensors would not be created.
Veem Backup Job Status & Veeam Backup Job Status Advanced	We fixed a compatibility issue for Veeam Backup Job Status and Veeam Backup Job Status Advanced sensors that did not support Veeam 13 for Veeam Backup Enterprise Manager and Backup Server. The sensors reported an error with the message that the JSONPath is incorrect in previous PRTG versions.

Fixed

WebGUI

Maps

We fixed an issue for public Maps that displayed an error Map refresh failed when you configured an External Link before in the Map Designer and clicked on the corresponding object in the public map. This issue also occurred with any Sunburst map object that you have added to your map. Opening the links to the individual objects would also lead to an error.

Note

Known Issue

Single Sign-on

We currently face an issue for Single Sign-on that does not work anymore when you update to this PRTG version 26.1.116.1498. For Single Sign-on configured with Entra ID in your PRTG, you will see the error message The server terminated an operation because it encountered a client request loop, for example. In the browser you could observe too many redirects and that the page is not working in certain cases. We are working on this issue with high priority.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 26.1.116.1498

sha256_exe 79DC26307D0888581E570C74A55532E1EF0713C7D126DD38EBEE516C379473A4
sha256_zip D7CFAC0F043330460CA7102EF6D9A830817387DE486AFA27BDF96A2CA1166192

Lab

Sensors

Proxmox VE Virtual Machine Status sensor	You can try out the experimental Proxmox VE Virtual Machine Status (BETA) sensor that monitors performance metrics and status of QEMU virtual machines on Proxmox VE clusters. To use this sensor type, please enter the Credentials for Proxmox in the device settings with API token authentication.
Proxmox VE Container Status sensor	You can try out the experimental Proxmox VE Container Status (BETA) sensor that monitors performance metrics and status of LXC containers on Proxmox VE clusters. To use this sensor type, please enter the Credentials for Proxmox in the device settings with API token authentication.
SNMP Custom String v2	We implemented a new setting for the SNMP Custom String v2 (BETA) sensor in the Specific Sensor Settings, named Interpret Result as. This setting basically converts the result from the SNMP endpoint into a string. You can select String (default), MAC address and IPv4 address for this setting. The sensor message will then show the format of the setting you have selected before, for example for MAC address it will display "01-02-03-04" as server response.
SNMP Custom v2	The Custom v2 sensor now supports string-encoded BITS values, for example MAC addresses, that are converted to a numeric format. Parsed BITS values will work with existing channel configurations.
SSL/TLS Certificate Sensor	You can try out the experimental SSL/TLS Certificate sensor (BETA) which is the successor to the SSL Certificate sensor and which was rewritten to also work on the Multi-Platform Probe. This sensor type monitors the certificate of a Secure Sockets Layer (SSL)/Transport Layer Security (TLS) secured connection. Please note that this sensor does not yet support the Use SOCKS proxy setting.
SIMATIC S7-300/400 Restart Overview	You can try out the experimental SIMATIC S7-300/400 Restart Overview sensor (BETA) that we introduce with this PRTG version. This sensor detects and classifies restart events (cold, warm, hot, planned or unplanned) from legacy Siemens PLCs (Programmable Logic Controller). It helps operations teams understand why and how often a PLC has restarted, which is often critical in diagnosing power losses, software crashes, or watchdog faults. The sensor uses Snap7 and S7 protocol to access the diagnostic buffer of the PLC.
SIMATIC S7-300/400 CPU Status	You can try out the experimental SIMATIC S7-300/400 CPU Status sensor (BETA) that we deliver with this PRTG version. This sensor connects to Siemens PLCs (Programmable Logic Controller) using the S7 protocol and reads key diagnostic values like CPU mode (RUN/STOP), OB1 cycle time, cycle load, and recent watchdog events. The data is collected read-only using Snap7 and provides OT teams with remote access to metrics that would otherwise require on-site inspection via TIA Portal.

Lab

PRTG APIv2

API

We fixed an issue for the endpoints api/v2/experimental/devices and api/v2/devices/{id} where the GET and PATCH results for Access Rights were not updated in PRTG API v2. The Access Rights settings are now updated immediately in PRTG APIv2 after you have created a new user group, for example. Previously, you had to execute another GET or PATCH request to receive the updated results.
You will now receive a list of creatable sensor types via endpoint /experimental/schemas/{parent} when you have created a group or device before. You will see if a sensor is creatable with the flag creatable=true and the result will contain a list of preconditions that have to be met in order to create the sensor.
We fixed an issue for the endpoint api/v2/experimental/schemas that did not check if it was valid to add a node to a certain partent ID, in this case the probe ID. For example, when you executed a POST request on this endpoint with parentid=1 and kind=ping, the schema would be returned without an error. Now you will receive an according error code in API v2 in this case asking you to check the ID of the object and that the schema ping does not match parent ID 1.
We improved the display of settings in the response code so that they correspond to user rights. For example, device settings that are returned via endpoint api/v2/devices and which have a notforreadonlyuser flag are now masked with asterics. This change also affects the api/v2/experimental/schemas endpoint.
We fixed an issue where an internal (500) server error occurred instead of a proper error message when you sent an empty group name with the request body to the endpoint api/v2/experimental/groups/{id}/device or api/v2/experimental/probes/{id}/device via POST request.

Lab

New UI

Dialogues	We fixed an issue for dialogues that disappeared partially behind the resize handler in the split view of the new UI. For example, when you have created a new device, you will receive a pop up dialogue success message object successfully created which could disappear partially behind the resize bars.
Device settings	We have added the Channel Unit Configuration section to the device settings, where you can configure default units for the channel types Bandwidth, Memory, Disk and File via dropdown menu. You can also use the Inherit From toggle for those settings.
Mobile view	We fixed an issue for the Device Settings page on mobile view where long texts where not displayed within the frame of the page but going out of bounds. We improved the display of pages where no data was found in the new UI for mobile view. For example, if you previously wanted to open a device or sensor list for a group without objects, the page would simply display a blank page with no content. You will now receive a proper error page with a message in this case that displays no matching results.
Object lists	You are now able to delete multiple objects in the Sensor list or Device list via bulk edit selection. You will see a confirmation dialogue that asks you if you want to cancel or confirm the deletion of the selected objects. You will receive an according error message if you do not have the necessary rights to delete certain objects.
Sensor status	We fixed an issue where you could not scroll down in order to see the full message when the sensor reported a down or warning message with a longer text.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German, Spanish, Dutch and Japanese language files.
Sensor languages	We updated the French, Portuguese, Russian, Chinese, Japanese and Dutch language files for certain sensor types.

Improved

Security

Webserver

We fixed a reflected Cross-Site Scripting (XSS) vulnerability in the tag parameter. An attacker could inject and execute arbitrary JavaScript code in the user's browser context. To perform a reflective XSS attack, an attacker has to induce the victim to issue a malicious request, for example, by providing a prepared link. This vulnerability can be tracked under CVE-2025-67833, with severity 8.1 - High (CVSS v3.1).
We fixed a reflected Cross-Site Scripting (XSS) vulnerability in the filter parameter. An attacker could inject and execute arbitrary JavaScript code in the user's browser context. To perform a reflective XSS attack, an attacker has to induce the victim to issue a malicious request, for example, by providing a prepared link. This vulnerability can be tracked under CVE-2025-67834, with severity 8.1 - High (CVSS v.3.1).

For further information please also see our Knowledge Base article: Vulnerabilities in PRTG prior v25.4.114.1032

Thanks to USD HeroLabs who made us aware of those vulnerabilities.

Application

We fixed a Denial-of-Service (DoS) vulnerability in the Notification Contacts functionality. An authenticated attacker could cause service disruption. This vulnerability can be tracked under CVE-2025-67835, with severity 3.5 - Low (CVSS v3.1).

For further information please also see our Knowledge Base article: Vulnerabilities in PRTG prior v25.4.114.1032

Thanks to USD HeroLabs who made us aware of the vulnerability.

Fixed

Sensors

VMware Datastore (SOAP) sensor

We fixed an issue for the VMware Datastore (SOAP) sensor that created an extra non-functioning channel when you have set your PRTG to a different language than English, for example German or Spanish. This channel did not deliver any values and therefore generated an error status, while the actual Free Space channel continued to function. Please note that existing VMware Datastore (SOAP) sensors will still show this extra channel when you update to this PRTG version, the fix applies when you create this sensor type new.

Windows Update Status (PowerShell) sensor

We fixed an issue for the Windows Updates Status (PowerShell) sensor which has been reporting the following error since the last Windows update from October 14th, 2025: Update history does not contain any entries. Please enable the sensor debug options and contact support for further help. The issue happened when your target system was Windows Server 2025 or Windows 11 updated to latest Windows patches.

Note

Update Notes

PRTG intermediate version 25.4.112.1189

To update to this Stable 25.4.114.1032 and subsequent PRTG versions, you must first install the following PRTG version: 25.4.112.1189 Stable. PRTG 25.4.112.1189 serves as an intermediate version when you want to update from older PRTG versions to this and subsequent versions. This step is necessary because we had to migrate our codesigning certificates to a new Cloud endpoint.

Note

Known Issues

Auto-update	This release contains a new code signing certificate and a corresponding intermediate version which will cause the auto-update process to run two times, please be informed that this could lead to longer update times and multiple reboots. Important: If you update your PRTG manually, please note that you need to update to the intermediate version 25.4.112.1189 first before you are able to update to the released PRTG version 25.4.114.1032.
Auto-Update/Signature	If you are running a canary channel, the auto-update process may run into problems. You need to either switch to the stable channel for one full update cycle or install the newest update by hand since there is no intermediate version for this version channel available, we are sorry for the inconvenience.
Signature	In certain cases, the PRTG core server does not start anymore after updating to PRTG 25.4.114 and the log file core.log contains the message: Signature of \Program Files(x86)\PRTG Network Monitor\32 bit\PRTG Server.exe is not valid or Signature of \Program Files (x86)\PRTG Network Monitor\64 bit\PRTG Server.exe is not valid The issue mainly affects PRTG installations that are offline or have limited access to the internet and happens if the code signing signature fails due to a missing trust chain in the trusted root certificates of the Windows certificate store. You can resolve the issue by adding the trusted root certificate for timestamp signature. For more information, see the Knowledge Base article After updating to PRTG 25.4.114, the PRTG core server does not start anymore.
Veeam Backup Job Status & Veeam Backup Job Status Advanced	We currently face an issue in the Veeam Backup Job Status and Veeam Backup Job Status Advanced sensors that do not yet support Veeam 13 for Veeam Backup Enterprise Manager and Backup Server. If you update your systems to this new Veeam version, the sensors will report an error with the message that the JSONPath is incorrect. When you create new sensors of that type, you will receive the following error message: The meta-analysis returned no valid results. Check if the sensor is compatible with the equipment. (code: PE069) We are currently working on a fix for this issue.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 25.4.114.1032

sha256_exe 7AE43FB27631364502DB8C5E635329E15B6542F9FE930B4A955C8A5B2CFA9BBF
sha256_zip C339DAF3FA37BCDD601CE8F5B620A926C7B2D3F313F810690F2DFC03DAAFFE59

Lab

PRTG API v2

API

You are now able to create the following sensor types with the new endpoint /experimental/devices/{id}/sensor via POST request: EXE/Script sensor. The new endpoint is listed under the Sensors section in Swagger UI and gives you information about supported sensors.
The schemas endpoint /api/v2/schemas now returns the lookupkey value correctly, for example lookupkey = intervalid or usergroupid.
We removed the field kind_variant from all endpoints. This field returned, for example, the value device when you executed a GET request on the api/v2/devices endpoint.
We changed the Schemas endpoint experimental/schemas/{kind} in PRTG API v2 so that it is replaced with the following endpoints: experimental/schemas/{parent}/post (for creating objects), experimental/schemas/{id}/patch (for updating objects) and experimental/schemas/{id}/get (for reading objects). You can use the include parameter as a filter for these endpoints in your requests.
The Web.log will now create log entries when you execute an API request in PRTG API v2 Swagger UI with an invalid or deleted API key. Requests via API v2 with invalid API keys were not logged before.

Lab

New UI

Mobile view

We fixed an issue for the logout button which was not displayed within the mobile view window and where you had to scroll down to the end of the page in order to logout.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German and Spanish language files.
Sensors languages	We updated the German and Spanish language files for certain sensor types.

New

Sensors

SNMP Linux Disk Free v2

With this PRTG version we introduce the new SNMP Linux Disk Free v2 sensor which is the successor to the SNMP Linux Disk Free sensor. This sensor monitors the free space on disks of a Linux/Unix system via SNMP. The SNMP Linux Disk Free v2 sensor is also compatible with the Multi-Platform Probe.

Improved

Security

HTTP Client	We updated our HTTP Client Axios for Browser and node.js to version 1.11.0 which fixes a critical vulnerability regarding the used form-data version.
Sensors	We hardened PRTG by improving input sanitization.

Improved

Sensors

Channel limits

We updated the sensor schema for certain sensor types that is used for setting channel limits. Affected sensor types are the Script v2, SSH Script v2 (BETA) and REST JSON Data sensor (BETA) sensor. The schema was updated to version 3, which ensures support for setting channel limits.

Fixed

Server

Activation Token	The Activation Token that shows the identifier of your license is now also displayed for PRTG offline license activations. You will see the Activation Token below your System ID on the License Status page when you select Manual (offline activation) for your license.
License activation	We fixed an issue that could occur during PRTG getting online activation data for a license and if PRTG encounters an exception at the same time. For example, in case of an 500 server error, PRTG would stop completely during activation resulting in an unavailable web interface. PRTG will now catch the exception and list it in the CoreActivation.Log. Furthermore, the PRTG web interface will be available and will direct you to the landing page /activation.htm in these cases.
Paessler PRTG Hosted Monitor	We fixed an issue that occurred on PRTG stable version 25.3.110.1313 for Paessler PRTG Hosted Monitor where invited users were not able to log in to the respective instance. The error message displayed was You are not authorized to access this PRTG instance.
Webserver	We fixed an issue regarding Overload Protection, where PRTG would display the message Warning! Overload protection is active! Click here to learn more even in cases when no Overload Protection was active due to how the value addition is handled for failed login attempts. For more information about Overload Protection and why it is used in PRTG, please see our Knowledge Base article: What is overload protection?

Fixed

Sensors

REST Custom v2

We fixed an issue for the REST Custom v2 sensor where the JSONPath setting for session based authentication was not correctly processed when you selected JSON format as Login Result Type. The login would fail with a 200 HTTP response code, instead 201 (created) should have been returned.

Note

Known Issues

Windows Updates Status (PowerShell) sensor

We are currently experiencing an issue with the Windows Updates Status (PowerShell) sensor, which has been reporting the following error since the last Windows update from October 14th, 2025: Update history does not contain any entries. Please enable the sensor debug options and contact support for further help. The issue happens when your target system is Windows Server 2025 or Windows 11 updated to latest Windows patches. We are currently investigating this issue with the highest priority.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 25.4.112.1189

sha256_exe A1C764BAA3D02040E35B5E938AE85B31DC25EDB277FF635A3BBD29E1724E0931
sha256_zip 35FAA3B7B3F773C2D35150A7C59DB79BD05D140AD08E51828572714A429EDE2D

Lab

PRTG APIv2

API

We fixed an issue where it was possible to move the ProbeDevice via endpoint /experimental/devices/{id}/move to another Group/Device/Probe. The issue occurred also for the actions clone and delete via APIv2. The ProbeDevice is fixed in PRTG and cannot be deleted, cloned or moved anymore via APIv2.
The IP address is now logged in the core logfiles, furthermore the Audit Log, in case of a failed login via ApiToken-Provider. The issue occurred in the PRTG application server where the IP address was not set in previous PRTG versions and thus could not be logged in those cases.
You are now able to create the following sensor types with the new endpoint /experimental/devices/{id}/sensor via POST request: AWS Cost sensor, Cloud Ping sensor. The new endpoint is listed under the Sensors section in Swagger UI and gives you information about supported sensors. All setting sections, including lookups, are supported for this sensor type.
We have added the field primary that is included in the response code when you execute a GET request on the endpoint /experimental/channels. When you filter for the primary field (true or false) you will receive a list of primary or non-primary channels accordingly.
We fixed an issue for the experimental endpoint /experimental/devices that returned the status PAUSED_UNTIL for paused objects by user when you executed a GET request. This status did not match our Schema and will now return PAUSED_BY_USER_UNTIL for objects that were paused by user until a certain date or time.
We added two experimental endpoints /experimental/usergroups/{id} and /experimental/usergroups to PRTG API v2 that return a list of created user groups or by ID when you set the include parameter first upon a GET request.
We improved the experimental endpoint /experimental/devices/{id}/sensor to accept certain sensor types via POST request when those sensor types have a version number in their name. The endpoint will now accept those sensor types with or without the version number. This change affects the AWS Cost sensor and Ping v2 sensor for now. You will also find an additional note under this endpoint listing the supported sensors.
We improved the handling for endpoints in PRTG API v2 that are not available for Paessler PRTG Hosted Monitor instances. For the endpoint /users/reset-password, for example, we now display a note that the endpoint is not available on Paessler PRTG Hosted Monitor. When you execute a POST request on this endpoint for password reset, you will receive a HTTP 501 error response that this method was not implemented yet.
We updated our Open API Specification available on API v2 Overview? regarding the endpoints in the sections Experimental and Deprecated.

PRTG application server

We fixed an issue for the PRTG application server that ignored parsing errors of the appserver.config.yaml and started with a default configuration. The PRTG application server will no longer start in this case and exit immediately, leaving a panic logfile with a message that explains the issue. This happened, for example, if lines for accesskey and clientuuid existed in the appserver.config.yaml.
We fixed an issue for the PRTG application server that occurred when you updated to PRTG version 25.2.108.1358. The PRTG application server would crash sporadically in certain cases and create a panic logfile with the message: panic: runtime error: invalid memory address or nil pointer dereference.

Lab

New UI

Dependencies	We added the option to select a sensor as dependency in the settings Schedules, Dependencies and Maintenance Windows. For the setting Dependency Type you will now see the radio button option Select a sensor. When you click on this option, a sensor selection UI appears, where you can choose from available sensor types.
Device settings	You are now able to set a Scanning Interval in the device settings via drop down menu. Additionally you have the option to set a sensor Status with the setting If a Sensor Scanning Fails.
Device templates	We added a selector for device templates that you can now open in the new UI of PRTG. The Confirm button is disabled when you do not make changes to the selection. When you change the selection for device templates, you are not able to close the dialogue but have to click Confirm instead.
Graphs	We fixed an issue for sensor graphs that were not correctly displayed in the new UI. For example, when you opened the Graphs tab of a sensor and used the Expand option and added one or two more channels, you would see only one channel graph in this case.
Monitoring	We fixed an issue where the vertical scrollbar on the Sensor List tab under Monitoring only appeared at the bottom of the page when you scrolled down. The vertical scrollbar is now visible on the whole page for the Sensor List if scrolling is necessary.
Mobile view	We fixed an issue that occurred when you logged out of the new UI on mobile view. Upon logout, an unknown error would be displayed.
Sensor overview	We fixed an issue on the sensor overview page that occurred sporadically. The issue could happen when you navigated to the sensor overview page and would show an error popup window on the channel gauge view.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German and Spanish language files.

New

ITOPs Board 3.22.1

Improvements and Fixes

This version comes with an improvement for Application Health Status where you can configure ITOps Board to send a notification when warnings or errors are raised for an integration or for the Vantage DX application. By default, notifications about application health are disabled. You must be an administrator to enable these notifications.

If you use a remote agent, you must update it in this release. This procedure must be performed by an administrator.

Additionally, the following application issues were fixed in this release of ITOps Board:

Upgrades failed if the user performing the upgrade had insufficient SQL server permissions. The installer now uses the Application Pool identity for the database upgrade.
The times of outages recorded in the SLA report are not displayed consistently for all regional settings. For some regional settings, the SLA report displays the times of outages but does not indicate am or pm.
If a child board is pinned to two or more parent boards, users in non-administrator roles are unable to view the child boards.
The application displays an SQL timeout error and becomes unresponsive.
SLA data is not calculated for business services and shows an error state.
Alerts related to a child board are not visible on the parent board.

New

Multi-platform probe 3.4.3

New supported sensors

A new version of the multi-platform probe is now available! With this release the multi-platform probe now supports the SNMP Linux Block Device I/O and REST JSON Data sensor. For more information about the supported sensors please see the manual, Multi-Platform Probe for PRTG

For detailed release notes about this release, see our Knowledge Base article: What are the release notes for the Multi-Platform Probe?.

New

Sensors

REST Custom v2 sensor	The REST Custom v2 sensor has left its BETA status and is now fully supported with this PRTG release. We introduced the REST Custom v2 sensor as experimental sensor with PRTG version 21.2.68.1492. The REST Custom v2 sensor queries a JSON or XML REST API endpoint and maps the according result to sensor values. During sensor creation, the REST Custom v2 sensor will now have a pre-filled value in the field Request URL for the section Specific Sensor Settings. The field displays https://%host/ to make it easier to identify the supported placeholder. The Request URL field was empty before in previous PRTG versions.
SNMP Linux Block Device I/O sensor	With this version we introduce the new SNMP Linux Block Device I/O sensor, which is the successor to the SNMP Linux Physical Disk sensor. This sensors monitors the input/output (I/O) on disks of a Linux/Unix system via SNMP. For more information about this sensor, for example, in case you change the SNMP version, please have a look at our Knowledge Base article: Why did my SNMP Linux Block Device I/O sensors stop working after I changed my SNMP version??
SSH Disk Free v2 sensor	The SSH Disk Free v2 sensor has left its BETA state with this PRTG version and is now fully supported. This sensor monitors the available disk space of a Linux/Unix system using Secure Shell (SSH). We released this sensor type as experimental (BETA) sensor with PRTG version 25.1.104.1946.

Improved

Sensors

REST API	We improved the session based authentication method for REST API based sensors to accept more success response codes in the range of 200-299. The Credentials for REST API only accepted the HTTP response code 200 OK for session-based authentication in previous PRTG versions.
Sensorlist.htm	To offer more details and information on a sensor, we added the following columns to the sensorlist.htm: Premeta (if the sensor requires a pre-meta scan), MinInterval and Momo (if it is a rewritten sensor type or not).

Fixed

Server

Add sensor	We fixed an issue that occurred on addsensor4.htm where large metascan entries during sensor creation could lead to an ajax timeout (PE:PE1113) in certain cases due to our update to Delphi 12.2 which also processes this page. This issue occurred, for example, if you tried to add SNMP Traffic sensors to a device with a large number of interfaces.
Dependency	We fixed an issue where a device and sensor with status paused by dependency could not be resumed. The issue occurred, for example, if a sensor was put into simulated error status and this sensor was not set as Master sensor for parent on the according device. In this case, you could not resume the sensor afterwards as it also went into the state paused by dependency. The sensor will now remain in the error status to be able to be resumed again.
License activation *Subscription only*	We fixed an issue where license activation for PRTG did not work in certain cases when the license activation file contained certain unicode/UTF characters that could not be decrypted. For example, when the license name included such a special character like Á or a long hyphen, you could observe the following error in the CoreActivationLog: No mapping for the Unicode character exists in the target multi-byte code page. The License status would also return Activation message processing has failed. in these cases.
Notification delivery	We fixed an issue for SMTP notification delivery when you have set your Notification Delivery settings to Use direct delivery with the built-in email server (default). This issue occurred with updating to PRTG version 25.2.106.1114 where email notifications were sent several times instead of only once and was happening only for the PRTG internal SMTP relay server.
Notifications	We fixed an issue for email notifications that were sent immediately after a sensor went from paused state into a resumed state and therefore got the status unknown first before collecting data. The issue occurred when you have set a State trigger to this sensor that applies when the sensor stays in an unknown status for a certain time period. PRTG will now recognize the transition from paused state (by user, by dependency, by schedule, by license and until) and will only trigger the notification when the configured trigger applies. You will now receive test notifications properly for MQTT messages within a notification template when you click on the button send test notification. In previous PRTG versions, PRTG would send the test notification with the prefix TEST, what therefore changed the topic you have subscribed to and thus you did not receive the according test notification. We have now added the wording TEST to the body of the notification, so that the topic will not change in this case.
Reports	We fixed an issue for reports that could not process umlauts correctly when you ran a report that included data files within the setting File Format and Delivery. For example, sensors with channel names that include umlauts were not displayed correctly in the xml file after generating the report with those sensors included. The issue occurred with PRTG version 25.1.104.1961.

Fixed

Sensors

NetApp SnapMirror v2 sensor	We fixed an issue for the NetApp SnapMirror v2 sensor that reported the value 0 for the channel Lag in certain cases. The issue occured only for the NetApp SnapMirror v2 sensors. In course of this, we changed the default name of NetApp SnapMirror v2 sensors to show the destination path instead of the source path in the sensor name to ensure that the NetApp SnapMirror v2 sensor uses the same instance name as its predecessor NetApp SnapMirror v1.
Ping v2 sensor	The Ping v2 sensor will now keep the dependency when you create a device template with an according Ping v2 sensor that is set as Master sensor for parent for the device. Previously, when you run an Auto-discovery with specific device templates before, the Ping v2 sensor would be created afterwards, however, it was not set as Master sensor like in the original device.
REST Custom v2 sensor	We fixed an issue for the REST Custom v2 sensor that ignored Custom HTTP Headers settings for the type Accept header. For example, if you defined an Accept header in the Custom HTTP Headers of the REST Custom v2 sensor, the header value would be overwritten in the previous PRTG version. The header is now transmitted correctly and you can see the value in the response of the Result of Sensor logfile. We fixed an issue for REST Custom v2 sensors that went into a down or warning state with the message Creation of rest_custom_v2_sensor failed: The setting "authentication_section.authentication_group.login_path" was not available when you updated to PRTG version 25.2.108.1358. A possible workaround for this issue was to pause and resume the sensors to make them run again.
SNMP v3	We fixed an issue for SNMP sensors that reported a timeout -2003 error in certain cases when you updated to the previous PRTG version 25.2.106.1114. The issue occurred in cases when you had SNMP sensors configured with SNMP version v3.
SSH Remote Ping v2 sensor	We fixed an issue that occurred in certain cases when you replaced your SSH Remote Ping v1 sensors with the successor SSH Remote Ping v2 sensors. We deprecated the SSH Remote Ping v1 sensor with PRTG version 25.2.108.1358. In this case, the SSH Remote Ping v2 accidentially would use the SSH host as device instead of the remote target, what resulted in wrong values. You could also observe that the sensor did not display any packet loss which worked with the v1 sensor before.
SSH sensors	We fixed an issue that occurred for certain SSH v2 sensors when you updated to PRTG version 25.2.106.1114. The issue happened only for v2 sensor types, that is why you have been able to observe it in these particular cases after the sensor migration for the SSH INodes Free v1 sensor. The sensor was not able to reconnect to the target device after a broken connection in some circumstances, which we improved now by changing the logic for reconnection.
WMI Event Log sensor	We fixed an issue for the WMI Event Log sensor where the handling for overflow values did not work properly. For example, when the sensor received and displayed values and you restarted the PRTG probe service, you could observe a high peak in the values afterwards.

Fixed

WebGUI

Alarms	We fixed an issue for Sensors With Alarms where objects were not displayed in the column Probe Group Devices. This issue was also fixed for the new UI and occurred only when you used Firefox as web browser.
PRTG Tickets	We fixed an issue in the PRTG Tickets tab that occurred in the Select a Group, Device or Sensor from the list section when you clicked on Add Ticket. The elements from the device tree would be overlapping in the search field in previous PRTG versions.

Note

Update Notes

Tree Version Update

The configuration file of this version is not downwards compatible with previous PRTG versions.

Note

Sensors

Common SaaS sensor	With this PRTG version we deprecate the Common SaaS sensor. You cannot add this sensor anew when you update to this PRTG version, however, existing sensor types continue to run. This sensor will not have a successor v2 sensor. You will receive an according TO DO ticket from PRTG when you update to this version.
SSH INodes Free sensor	With this PRTG version we discontinue the SSH INodes Free v1 sensor. We announced the deprecation of the SSH INodes Free v1 sensor with PRTG version 25.2.106.1114 where also existing SSH INodes Free sensors were migrated to their successor v2 sensors. Please note that existing SSH INodes Free v1 sensors will stop working when you update to this PRTG versions, however, this does not apply for migrated SSH INodes Free sensors. It is not possible to create an SSH INodes Free v1 sensor anymore. For more information about sensor deprecation and discontinuation, please see our Knowledge Base article: What do deprecation and discontinuation in the context of a sensor mean?
Sensor migration	With this PRTG version, the following sensor types are migrated to their successor v2 sensors: SSH Meminfo, SSH Load Average and SSH Remote Ping sensor. PRTG will sent an according TO DO ticket with all relevant information. We announced the deprecation of SSH Meminfo, SSH Load Average and SSH Remote Ping sensor with PRTG version 25.2.108.1358.
Discontinuation of Python Script Advanced sensor with PRTG 25.x.110	With this PRTG version we discontinue the Python Script Advanced sensor. We announced the deprecation of this sensor type with PRTG version 25.1.104.1946. Running sensors of this type will stop working and report an error message about the disontinuation and the Python installation will be removed when you update to this PRTG version. To ensure further monitoring, please use the successor Script v2 sensor instead and make sure to adjust your custom scripts in advance. For more information please see our Knowledge Base article: What do deprecation and discontinuation in the context of sensors mean? Read here for differences and more information about the two sensors: Why should I use the Script v2 sensor? We also provide information on how to migrate your scripts with this Knowledge Base article: How can I make my Python scripts work with the Script v2 sensor?

Note

Server

License information

Subscription only

With this PRTG version we display an Activation Token on the License Information page. This token shows the identifier of your activated license. The Activation Token is displayed for Paessler PRTG Enterprise and Subscription licenses and valid also for offline license activations.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 25.3.110.1313

sha256_exe 16649C98C3EBF43D982E4798448661140704D6209751298AEA4B26A4A3C9D674
sha256_zip 82BF773F808FFEE8ED9AB05F1520E296C2499A1D3430F4170CE7ED64472B4913

Lab

Sensors

REST JSON Data sensor

You can try out the experimental REST JSON Data sensor (BETA) that we introduce with this PRTG version. This sensor queries an HTTP endpoint which returns JSON data in a well defined format. The format is the same as for the Script v2 sensor. Depending also on the JSON response, the sensor will create the channels Status and HTTP Status, amongst others. This sensor is also compatible with the Multi-Platform Probe.

Lab

PRTG API v2

API

We improved our internal naming conventions to be more consistent in the format. In course of this, we renamed the property _inheritanceSource to to _inheritancesource.
We implemented a new endpoint /experimental/devices/templates that returns a list of available device templates upon GET request.
You are now able to create a Ping sensor with the new endpoint /experimental/devices/{id}/sensor via POST request. The new endpoint is listed under the Sensors section in Swagger UI and gives you information about supported sensors: This endpoint does not yet support all sensor types. Currently only the following sensors are supported: * Ping. The body of the POST request contains the settings of a ping sensor as defined in the schema, for example, required fields and settings sections.
We fixed an issue where a remote probe returned the status CONNECTED in the PRTG API v2 under yourserver:1615/api/v2/probes/ID although it was not approved yet. You will now receive the correct status for the remote probe PENDING_APPROVAL in this case.
You can now send a GET request on the endpoints /experimental/objects or experimental/groups/{0} with the include parameter and value all. Previously, the inheritanceSource would return unknown_reference_object_type for the type field. You will now receive correctly REFERENCED_ROOT.

PRTG application server

We improved the supported number of ciphers used in the TSL configuration for Default security (TLS 1.3, TLS 1.2) (recommended) that you can edit in the PRTG Web Server settings for Connection Security. The setting for Weakened security will still support older TLS versions and all current cipher suites used in the PRTG application server.
We fixed an issue that occurred in previous PRTG Preview version 25.3.109.1353 where an HSTS( Strict-Transport-Security) header was not sent correctly by the application server. The PRTG application server will now no longer send an example HSTS header during installation. Please use appserver.config.yml for configuration of an own HSTS header.
We fixed an issue for the PRTG application server that got stuck in certain cases during shutdown process and where it has hung up during the step unsubscribing from core notifications. As a result, also core and web server processes were not able to shutdown. A possible workaround was to manually stop the process.

Licenses

Subscription only

We fixed an issue that occurred in certain cases when you have added a PRTG Subscription license and when displaying PRTG in the new UI was not possible. PRTG Subscription license types were enabled in the PRTG core, however, in certain cases the PRTG application server did not recognize them as valid. When you clicked on Open new UI button on the login page, PRTG would show An unknown error occurred in these cases.

Lab

New UI

Interface

We updated our typography throughout the New UI to match the design system.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German, Spanish and Japanese language files.
Sensor Languages	We updated the language files in German, French, Portuguese, Russian, Chinese, Japanese and Dutch for certain selected sensor types.

Improved

Security

Auto-discovery	We hardened PRTG in relation to CVE-2024-12833 by applying further sanitization to names objects.
Webserver	We hardened PRTG against a possible XSS (Cross-Site Scripting) vulnerability. We considered this vulnerability as medium with a CVSS score of 6.5 and the vectors as follows: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

New

Multi-platform probe 3.3.0

New Architecture

A new version of the multi-platform probe is now available! With this release the multi-platform probe has undergone a major re-architecture to deliver you a better overall user experience. Key improvements of the new multi-platform probe architecture are enhanced performance and reliability, allowing you to deploy more sensors per probe while reducing memory consumption and overall resource usage. For example, previously, you were required to have 2 CPU cores to support 200 sensors. With the new architecture, the multi-platform probe can support up to 400 sensors with the same setup. Please see the manual, Multi-Platform Probe for PRTG , for the updated system requirements.

In addition to these user-facing enhancements, we made the probe easier to maintain and improve, enabling us to streamline the development of new features, maintenance, and bug fixes.

For detailed release notes about this release, see our Knowledge Base article: What are the release notes for the Multi-Platform Probe?.

New

Sensors

NATS Server Overview sensor	We introduce the new NATS Server Overview sensor with this PRTG release that monitors a NATS Server by connecting as a NATS Client in order to retrieve monitoring data. In case of Jetstream enabled NATS servers, the NATS Overview sensor will display the additional channels Jetstream Memory Used (%), Jetstream Storage Used (%), Jetstream Memory Reserved (%) and Jetstream Storage Reserved (%).
SNMP CPU Usage sensor	We introduce the new SNMP CPU Usage sensor with this PRTG version that is the successor sensor for the SNMP CPU Load sensor. This sensor type monitors the system load via the Simple Network Management Protocol (SNMP). This sensor type was rewritten to be compatible with the Multi-Platform Probe.
SNMP UPS Status sensor	With this PRTG version, the SNMP UPS Status sensor left its BETA status and is now fully supported. This sensor type monitors the status of an uninterruptible power supply (UPS) via Simple Network Management Protocol (SNMP). We introduced this sensor type as experimental sensor with PRTG version 24.4.102.1351.
SSH Load Average v2 sensor	With this PRTG version, the SSH Load Average v2 sensor left its BETA status and is now fully supported. This sensor monitors the load average of a Linux/Unix system using Secure Shell (SSH). We introduced this sensor type as experimental sensor with PRTG version 24.4.102.1351.
SSH Meminfo v2 sensor	With this PRTG version, the SSH Meminfo v2 sensor left its BETA status and is now fully supported. This sensor monitors the memory usage of a Linux/Unix system using Secure Shell (SSH). We introduced this sensor type as experimental sensor with PRTG version 24.4.102.1351.
SSH Remote Ping v2 sensor	With this PRTG version, the SSH Remote Ping v2 sensor left its BETA status and is now fully supported. This sensor remotely monitors the connectivity between a system running Linux/macOS and another device using Internet Control Message Protocol (ICMP) echo requests ("ping") and Secure Shell (SSH). We introduced this sensor type as experimental sensor with PRTG version 24.4.102.1351.
SNMP Linux Load Average v2	With this PRTG version we introduce the new SNMP Linux Load Average v2 sensor that is the successor sensor for SNMP Linux Load Average. This sensor type was rewritten to be compatible with the Multi-Platform Probe. The SNMP Linux Load Average sensor monitors the system load average of a Linux/Unix system via the Simple Network Management Protocol (SNMP).
SNMP Linux Meminfo v2	With this PRTG version we introduce the new SNMP Linux Meminfo v2 sensor that is the successor sensor for SNMP Linux Meminfo sensor. This sensor type was rewritten to be compatible with the Multi-Platform Probe. Please note that the channel Available Memory (%) has been renamed to Free Phyiscal (%) and vice versa to better match its purpose, for example, Available Memory (%) should be the memory that is available for applications if the operating system was also reclaiming buffers/cache space, whereas Free Phyical (%) is the value which is not in use currently.
SNMP Memory v2	We introduce the new SNMP Memory v2 sensor with this PRTG version that is the successor sensor of the SNMP Memory sensor. This sensor type monitors the memory usage of a system via the Simple Network Management Protocol (SNMP). This sensor type was rewritten to be compatible with the Multi-Platform Probe.

Improved

Server

Licenses

We improved our handling for licenses to accept more formats when you have to use the Activation Data file in order to activate PRTG on an offline system. This file will be sent as .dat or .txt file and it is needed during the manual activation process.

License activation

Subscription only

We improved the behavior of PRTG when you have activated a PRTG Subscription or Paessler PRTG Enterprise Monitor license that has expired or is going to expire. You will now receive a growl message that displays when your PRTG Subscription license has expired or will expire. In case of license expiration, the License Status will show the activation data is no longer valid. Additionally, PRTG requests the value from validuntil in the activation data as well when you activated it with a Paessler PRTG Enterprise Monitor license first on an online system and later switch to an offline environment.

Improved

Sensors

SNMP Disk Free v2 sensor

We added support for flash memory classification in the SNMP Disk Free v2 sensor. Previously, disks reported as flash memory in the SNMP Disk Free v2 sensor were not listed during sensor creation.

Improved

WebGUI

PRTG logo

We replaced our old PRTG gauge logo with a new one that was updated in colour and style throughout PRTG. The logo has also changed in the new UI in various locations, for example, in the tab as the favicon display or as the Monitoring icon.

Changed

Server

SMTP authentication

Microsoft announced that Exchange Online will permanently remove support for Basic authentication with Client Submission (SMTP AUTH) in September 2025. To further maintain support for SMTP settings and email delivery in PRTG, please see the following Knowledge Base article: How can I use SMTP with the deprecated Microsoft Exchange authorization?

Fixed

Server

Active Directory	We fixed an issue that occurred when your active directory server was not accessible and you wanted to add a user group to your PRTG. You would receive a Bad Request pop-up instead of a proper error message. PRTG will now display Active Directory Domain not found under Active Directory Group in the User Group Settings in these cases.
API keys	We fixed an issue for the endpoint getdesktoptoken.htm, that returned the message unauthorized when you had Single Sign-on configured and created an API key for PRTG Multiboard. The issue occurred when you were logged in with the relevant Single Sign-on user to whom the API key was assigned. PRTG will now return the according API token and only display the error message when the user has no assigned token.
HTTP errors	We fixed an issue for returned errors on certain not accessible pages in PRTG that previously reported a not found error. PRTG will now return a HTTP 403 forbidden path error in those cases.
Logging	We fixed an issue where log messages with the text Wrong period in cache where wrongly logged as exceptions when you changed a graph period under Graph Settings in the User Interface setup.
Notifications	We fixed an issue for notification templates where settings for Microsoft Teams and Slack notifications were cleared in certain cases. The issue occurred when you selected notification templates via multi-edit menu to add tags. After you have added tags for your notification templates and saved the changes, the set checkboxes under Custom Content in the Microsoft Teams and Slack notification templates were cleared.
PRTG activation	PRTG will now list the actual System ID in the Core.log and in the PRTG Administration Tool to help solve license activation issues in case of incorrect returned System IDs. When you wanted to perform an offline activation of PRTG with a Paessler PRTG Enterprise license, for example, and the System ID was incorrect, you would get the error message The local system ID does not match the system ID returned by the activation service. This information is not available on PRTG remote probe systems.

Fixed

Sensors

HPE 3PAR Drive Enclosure	We fixed an issue for the HPE 3PAR Drive Enclosure sensor that reported the error message N/A could not be converted to integer in certain cases. The issue occurred when the drive controller reported an invalid temperature or no temperature at all.
HPE ProLiant Memory Controller sensor	The HPE ProLiant Memory Controller sensor now supports additional lookups for systems using Adaptive Double Device Data Correction (ADDDC). Previously, the sensor reported an error undefined lookup value (16) in such cases.
SNMP Disk Free v2	We fixed an issue for the SNMP Disk Free v2 sensor that displayed the settings Type and Size for the monitored disks in the sensor Settings. Those columns should only be available during sensor creation. The SNMP Disk Free v2 sensor will now only display the columns Type and Size during sensor creation in the result columns.
SNMP v3	We fixed an issue for SNMP v3 error messages that did not reflect that the error was due to a timeout. In case of an SNMP timeout, the error message will now display Timeout Error: The sensor failed to communicate with the target system.
sFlow sensors	We fixed an issue in the sFlow sensor to support 32bit numbers in the SourceID field. In previous PRTG versions, this packet format was not accepted by PRTG. This change allows you to monitor now specific devices, for example Neptune (NPT) routers.

Note

Known Issues

Notification delivery	We currently face an issue with SMTP notification delivery when you have set your Notification Delivery settings to Use direct delivery with the built-in email server (default). This issue occurrs with updating to PRTG version 25.2.106.1114 where email notifications are sent several times instead of only once. Additionally, you will notice an error growl message: Your PRTG core server is currently unable to send email notifications. Check your configuration..
SNMP v3	With updating to PRTG version 25.2.106.1114, SNMP sensors monitoring devices via SNMP v3 may report a timeout error (SNMP error -2003) in certain rare cases. A probe restart only helps temporarily. In case you received a preliminary fix for this issue, we recommend that you update your PRTG only when we deliver a fixed library in the upcoming versions.
SSH sensor migration	There currently is an issue that occurrs in certain rare cases after sensor migration of SSH sensors. The SSH Inodes Free v2 sensor, for example, ran into a timeout under certain circumstances when you updated to PRTG version 25.2.106.1114 in which we introduced the migration process for this sensor type. In the Result of Sensor log, that is created when you enable Store Result for this sensor, you could also observe a connection failure and timeout error. We are investigating the problem with the highest priority.

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 25.2.108.1358

sha256_exe 5DD6D0FEC1071FC5F90CF05E81965BB01CC47726CF63FCA37421DE60E927405C
sha256_zip 144D4E61D3E095550C22542919F0C5859CFDF27683351F03FA1429C53ABC1AD5

Note

Sensors

Deprecation of SFTP Secure File Transfer Protocol sensor with PRTG 25.x.108	With this PRTG version we deprecate the SFTP Secure File Transfer Protocol sensor. Existing sensors will continue to run but you will not be able to add this sensor anew when you update to this PRTG version. Currently there is no successor sensor planned for this sensor type. You will receive an according To Do ticket in PRTG about this sensor deprecation.
Discontinuation of SSH INodes Free sensor	With this PRTG version we discontinue the SSH INodes Free sensor. We already announced the deprecation of this sensor type with PRTG version 25.2.106.1114. Running SSH INodes Free sensors on your PRTG installation will stop working when you update to this PRTG version. Migrated sensor types from SSH INodes Free to the successor v2 sensor version are not affected. You cannot add the SSH INodes Free sensor anymore when you update to this PRTG version. Please use the successor sensor SSH INodes Free v2 in this case which left its BETA status with PRTG version 25.1.104.1946.
Deprecation of certain sensor types with PRTG 25.x.108	With this PRTG version we announce the deprecation of the following sensor types: SSH Meminfo, SSH Load Average and SSH Remote Ping sensor. Existing sensor types will continue to run when you update to this PRTG version, however, you cannot add those sensors anymore as new. PRTG will also create an according To Do ticket. For more information on sensor deprecation, please see our Knowledge Base articles: What sensors are deprecated and what are their successors or alternatives? and What do deprecation and discontinuation in the context of sensors mean?
Upcoming sensor migration with PRTG version 25.x.110	With this PRTG version we announce the sensor migration that will happen with PRTG 25.x.110 for the following sensor types: SSH Meminfo, SSH Load Average and SSH Remote Ping sensor. PRTG will sent an according TO DO ticket with all relevant information. The sensors will be migrated to their successor types SSH Meminfo v2, SSH Load Average v2 and SSH Remote Ping v2 sensor. Those successor sensors left their BETA status with this PRTG release.

Lab

Sensors

REST Custom v2

We added the option to use session-based authentication with the REST Custom v2 (BETA) sensor in order to monitor devices that cannot be integrated into PRTG yet. You will find additional settings Session Based Authentication in the device settings under Credentials for REST API where you can define an Authentication Method.

Important:: Please note that existing REST Custom v2 sensors will go into down or warning state with the error message Creation of rest_custom_v2_sensor failed: The setting "authentication_section.authentication_group.login_path" was not available when you update to this PRTG version. To solve this issue, please pause and resume the affected sensors to make them work again. We will provide a fix for this issue with the upcoming PRTG versions.
We improved the logging for the REST Custom v2 sensor concerning passwords, placeholders and API keys that you can configure under Credentials for REST API in the device settings. For example, if you run an auto-discovery with device template for this sensor type, no sensitive data will be logged in the CoreAutoDiscovery logfile or the data is masked and therefore unreadable.

SNMP CPU Usage sensor

You can try out the experimental SNMP CPU Usage sensor (BETA) which is the successor of the SNMP CPU Load sensor. This sensor type monitors the system load via the Simple Network Management Protocol (SNMP). Please note that you need to enable the PRTG BETA feature under Experimental Features in the PRTG Setupfirst in order to use this sensor.

Lab

PRTG APIv2

API

We implemented a new endpoint /experimental/devices/{id}/move in our PRTG APIv2 that allows you to relocate objects within the monitoring structure via POST request. In this new endpoint, you can enter the ID of the device that you want to move in an additional field. In the request body, you need to add the parent and the position where the device should be placed.
We implemented a new GET endpoint under api/v2/experimental/license in the Systems section of Swagger UI. This endpoint is only accessible if you are logged in as a PRTG administrator. You can receive information about the current PRTG license with the fields start_date, end_date, maintenance_end_date via GET request.
We fixed an issue for GET endpoints in PRTG API v2 that returned a 200 OK response with a default set of fields when you, for example, had a typing error in the inheritance parameter. The API will now return a 400 Bad Request in this case with the message the request could not be processed.
We added a new filter operator Ancestor ID for experimental list endpoints in PRTG API v2. The filter returns all objects that have the specified ID as an ancestor in their object hierarchy. Affected experimental endpoints are, for example, /experimental/channels and /experimental/sensors.
We fixed an issue where the pagination headers for all experimental endpoints related to the wrong endpoint. In most of the cases, the headers pointed to endpoints that were not set as experimental. For example, /api/v2/experimental/devices related to /api/v2/devices instead. The pagination headers will now point to the same endpoint as the requested URL.
We implemented a new GET endpoint /experimental/objects that allows you to receive probes, groups, devices, sensors and channels from a single endpoint.

PRTG application server

We improved the performance of the PRTG application server used on larger installations and reduced memory consumption on all installations.

Lab

New UI

Home page	We added an extra card that displays the current version of PRTG that you have installed. The card shows the title Your version of PRTG. You can also see previous and additional versions with the link View version history / release notes of previous versions.
Notification trigger	To make the Notification Triggers more visible, we moved the Notification Triggers section from access via button to an extra tab. You will also have the possibility to access the Notification Triggers via context menu.
Monitoring	We fixed an issue that occurred when you clicked the split view buttons on the Monitoring page from left to right or vice versa and when the developer tools were opened in the browser at the same time. You would receive an unknown error growl message in these cases and when you used Chrome as browser for PRTG.
Tabs	We fixed an issue where the link back from the new UI to classic web interface resulted in an error page when you navigated to the History or Logs tab of the local probe. PRTG would return an error page There was a problem... when you clicked on Open Classic UI in the relevant tabs.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German, Spanish, French, Russian, Chinese, Portuguese and Dutch language files.

New

Itops Board 3.20.0

Improvements and Fixes

This version comes with a new setting that allows administrators to customize the time interval at which ITOps Board sends notifications.

Additionally, the following issues were fixed in this release of ITOps Board:

Dialog boxes that allow users to edit table columns do not work well with screen readers. These tables have been updated for improved accessibility.
When you attempt to open the Alerts tab on a board, the tab does not load.
When the alert count for a board changes, the interface does not automatically refresh and show an updated alert count.

Improved

Security

Webserver

We hardened PRTG against open redirect vulnerabilities where URL forwarding to external sites was possible.

Improved

Sensors

Device templates	We adapted our device templates so that they also contain the new v2 sensor types. Former deprecated sensors that have an according v2 sensor type as successor were removed from the device templates. For example, when you execute an auto-discovery with device template for Server DNS, the DNS v2 sensor will be added afterwards.
VMware Datastore (SOAP) sensor	The VMware Datastore (SOAP) sensor now includes limits for the channel Free Space by default. The Lower Warning Limit (%) is set to 10 and Lower Error Limit (%) is set to 5. These thresholds are set by default when you create this sensor type new or when you did not have set custom limits before in a previous PRTG version for this sensor. When you have set custom limits before, those settings will be kept when you update to this PRTG version.
Script v2 sensor	The Script v2 sensor now supports native executables. This means that the sensor can now run arbitrary executable files (Linux) or *.exe (Windows). The native executable file should be stored on the probe system. On Linux systems, executables require execute permissions to run. To run Python scripts, this sensor requires that Python 3 is within PATH.
Sensor status	We improved the error message text in the sensor status so you will receive a proper error message instead of a generic one when certain exceptions occur.

Improved

Server

License

We improved our license handling and error messages on the License Information page in PRTG. For example, when you want to change your license and the key is not valid or wrong, you will receive an according error message Activation successful - using previous license key. PRTG will then use the previous key as stated in the message instead.

Important

Sensors

SSH INodes Free sensor migration

Your SSH INodes Free sensors will be migrated to the successor SSH INodes Free v2 sensors when you update to this PRTG version and higher. We already announced the upcoming sensor migration with PRTG version 25.1.104.1946. After successful sensor migration, your SSH INodes Free v2 sensors will keep the ID, settings and historic data of the former SSH INodes Free sensors. You will receive an according TO DO ticket in PRTG about relevant device template migration and under which path you can find a backup of the original files. For more information about sensor migration, please see the Knowledge Base article: What is a sensor migration?

Fixed

Server

Geo location	We fixed an issue for geo location information that was displayed in native language for the according country, region or city. The issue occurred because our location service provider updated their API which had impact on the location language. The locations in the Geo Map will be displayed in English again when you update to this PRTG version.
PRTG application server	We fixed an issue that occurred with PRTG version 25.1.104.1946 where the application server service stopped running or did not run at all in rare cases, depending on the number of sensors and system resources, for example. As a result, you could not use the new PRTG user interface. You could also observe that the application server was consuming much more memory in these cases.
SMTP settings	We fixed an issue that occurred when you have set your SMTP server settings to Continue delivery if session is disconnected by client in order to receive email notifications in certain cases. PRTG would cut the connection to the SMTP server before getting any confirmation in those cases. PRTG will now send a QUIT verb to the SMTP server before cutting the connection.

Fixed

Sensors

HTTP Transaction sensor	We fixed an issue for the HTTP Transaction sensor that occurred in previous PRTG versions where the sensors went into Down state after updating to PRTG 22.2.77.2204 in certain cases. A possible workaround was to set the Monitoring Engine to use the Compatibility engine mode in order to monitor the URL what helped in certain cases. The issue happened because the HTTP request cookie was not transferred for all following requests in a non compatibility mode. In some cases the HTTP Advanced sensor was also affected by reporting that the connection was refused and it would work again with the Compatibility engine mode. We fixed an issue for the HTTP Transaction sensor that occurred when you chose the option Compatibility engine under the option Monitoring Engine section and you set a text value for example ccc in the option Response must not include field in the sensor settings. The sensor then would have displayed a down status with the message URL #1 Warning: RegEx does not match [ccc].
LDAP sensor	We fixed an issue for LDAP sensors that could not be created via device template in certain cases. The issue occurred when you created a device template for an LDAPS server with accordingly configured sensors before, that is LDAP Specific has to be set to Use LDAP over SSL in the Connection Security. The sensors would be created afterwards but the settings were configured wrongly to use LDAP (Port 389) for unsecure connections.
NetApp SnapMirror v2	We fixed an issue for the NetApp SnapMirror v2 sensor that reported the error message The queried field "resnyc_failed_count" is empty in certain cases. The issue occurred, when you monitored a NetApp SnapMirror system that never had a failed resync or update.
OPC UA sensors	We fixed an issue for OPC UA sensors that went into error state in certain cases when you have set the Security Mode in the Credentials for OPC UA of your device settings to None. The issue occurred, because the sensors still used a previously set client certificate although you disabled the Security Mode in the device settings.
SNMP v3	We fixed an issue for SNMP sensors that reported the error message SNMP error -2011 and Could not create SNMP session (-1)-2011 in certain cases when you updated to the latest PRTG version 25.1.104.1961. The issue occurred for sensors using SNMP v3 for monitoring as set version.
Sensor count	We prevented a possible access violation that could happen in rare cases when a probe created too many sensors at once. The fix applies for classic remote probes as well as the Multi-Platform Probe. On Windows systems, the error could be displayed as Invalid access to memory location with error code 998.
WMI Vital System Data v2 sensor	The WMI Vital System Data v2 Sensor now offers the counter Memory:Cache Bytes when you add a new sensor under the section Vital System Data Readings Accessible Using WMI.

Fixed

Paessler PRTG Enterprise Monitor

Single Sign-on

Subscription only

We fixed an issue that occurred when you had Single Sign-on configured in your PRTG and changed the license key to a Paessler PRTG Enterprise Subscription license type. In those cases, the Single Sign-on login would not work anymore and the Single Sign-On Settings under System Administration would be missing additionally after changing the license type.

Improved

WebUI

Sensor overview

We improved the wording for sensors that is displayed in the sensor overview popup when you hover over a sensor in the device tree.

Note

Update Notes

Tree version update

The configuration file of this version is not downwards compatible with previous PRTG versions.

Note

Sensors

Deprecation of SSH INodes Free sensor with PRTG 25.x.106

With this version we announce the deprecation of the SSH INodes Free sensor, that will be migrated to a successor SSH INodes Free v2 sensor when you update to this PRTG version. SSH INodes Free v1 sensors cannot be added anew when you have updated to this PRTG version. For more information about sensor deprecation and discontinuation, please see our Knowledge Base article: What do deprecation and discontinuation in the context of sensors mean?

Deprecation of Python Script Advanced Sensor with PRTG 25.x.106

With this version we deprecate the Python Script Advanced sensor that we already announced with PRTG version 25.1.104.1946. The Python Script Advanced cannot be added anew when you update to this PRTG version, however, existing sensor types continue to run. Please use the successor sensor Script v2 instead. For more information please see our Knowledge Base article: What do deprecation and discontinuation in the context of sensors mean?

Read here for differences and more information about the two sensors: Why should I use the Script v2 sensor?

We also provide information on how to migrate your scripts with this Knowledge Base article: How can I make my Python scripts work with the Script v2 sensor?

Note

Installer

Security

You can verify the authenticity of the PRTG installer with the Secure Hash Algorithms for the following versions and release channels:

Stable 25.2.106.1114

sha256_exe CBEB1C5ECD86060B2866E1E6C56844FDA63CECB3EB29A7551DA94DB7066F95A0
sha256_zip ED2E78563E54F187F3E6078DE85D0671B246E393AB154A4B0EBEA59A15659C38

Lab

PRTG API v2

API

You can now receive and edit location information with the include parameter set to locationgroup via GET and PATCH request on the devices and group endpoints. To see the location of an object, use the /{id} or list endpoint for a certain object type and make sure to include locationgroup via the include parameter.
We added the sections /experimental/users/{id} and /experimental/users for GET requests in the api/v2/oas.
You are now able to create a group via PRTG API v2 and an according POST request on the endpoint /api/v2/experimental/groups/{id}/group and /api/v2/experimental/probes/{id}/group .
You are now able to edit group settings via PRTG API v2 and an according PATCH request on the endpoint /api/v2/experimental/groups/{id}.
You can now delete a group or a sensor with a DELETE request in the experimental section /experimental/groups/{id} or /experimental/sensors/{id}. If the request is successful, you will receive a 204 response code.
We updated the /devices/{id} and /groups/{id} to receive and display information about the status of auto-discoveries. When you execute a GET request on the mentioned endpoints, you will see the additional section about auto-discovery with the fields active, progress and last_autodiscovery, which display whether an auto-discovery is currently running, the progress and when the last auto-discovery ran respectively. Please make sure to set the include parameter first for the section autodiscovery.
We fixed an issue that occurred when you sent a PATCH request to the /devices/{id} endpoint for the settings group discoverytypegroup and the devicetemplate value was not set. The returned error response code was 400 with the message BAD REQUEST in those cases.
We fixed an issue for the dbport field in the dbcredentials used for Credentials for Database Management Systems in the device settings. When the default value of that according field was set to 1, for example, the request would fail in the PRTG API v2.

Lab

New UI

Auto-discovery

You will now see an indicator bar in your device tree view indicating there is an auto-discovery session running in the device tree. If you have more than one sessions running the indicator bar will display the total number.

Improved

Various

All parts of PRTG	Various other minor fixes and improvements, updated user manual.
Languages	We updated the German and Spanish language files.

Release notes for the "stable" release channel

June 3rd 2026 - 26.2.120.1449

New

Sensors

SNMP Custom String v2

SNMP Printer v2

SNMP RMON v2 sensor

New

Server

Reports

Improved

Security

Webserver

Improved

Sensors

Microsoft 365 Mailbox sensor

Changed

Server

Activated PRTG Database (BETA)

Changed

Sensors

Custom sensors

Changed

WebGUI

System Status

Fixed

Server

Geo map

NATS setup

PRTG Core service

Fixed

Sensors

NetApp SnapMirror v2

DNS v2 sensor

Ping v2 sensor

Fixed

WebGUI

Auto-discovery

Fixed

MultiBoard

API Keys

Note

Known Issues

PRTG Database migration (BETA)

PRTG installer

Note

Installer

Security

PRTG Database (BETA)

Lab

Server

PRTG Database (BETA)

Data migration

Lab

Sensors

SIMATIC S7-300/400 CPU Restart Overview sensor

SIMATIC S7-300/400 CPU Status sensor, SIMATIC S7-300/400 CPU Restart Overview sensor

SNMP Custom String v2 sensor

SNMP Traffic v2

Lab

PRTG APIv2

API

Lab

New UI

Channel units

Device tree

Monitoring

Objects

User session

PRTG Home page

Improved

Various

All parts of PRTG

Languages

March 25th 2026 - 26.1.118.1380

Improved

Security

Authentication

New

Sensors

Release notes
for the "stable" release channel