This article applies to PRTG Network Monitor 19.x.50 and 19.x.51

PRTG 19.x.51 Was Not Available for Some Time

PRTG Network Monitor version 19.3.51.2725 was available for download from July 31, 2019 until August 5, 2019. We took it offline on August 5 because of our customers' feedback.

About 5% of our customers who updated to this version reported serious issues with their monitoring after the PRTG server restart. We consider the number of reports as too high for our quality standards and decided to take the version offline on Monday, August 5, as a precaution to not let more customers run into a potentially critical issue.

We apologize for any inconvenience this may have caused you. We always do our utmost to deliver high quality software, but this time our quality gates were not enough. We are currently investigating the issue and will provide a new, better version as soon as we can. Update: PRTG 19.3.51.2830 is available for download since September 10.

Note: If you already run PRTG version 19.3.51.2725 and do not experience issues in this context, there is no need to act and you can just keep PRTG 19.3.51.2725 running. The issue usually directly appears after the update if you are affected. If you have any questions, please do not hesitate to contact us.

More Details

With the update to PRTG 19.3.51.2725, customers reported that CPU load went up to 100% and sensors switched to the gray Unknown status, not reporting any data. This happened when PRTG did a graph cache recalculation. While a cache recalculation is nothing uncommon and must be done from time to time, it is not expected to completely stop monitoring on the PRTG server for hours as it happened in some cases. Sometimes a restart of the server helped, but not in every case.

If you downloaded the installer but did not install the version yet, we strongly recommend that you do not perform the update and that you wait until we can provide a fixed version. If you already successfully updated to PRTG version 19.3.51.2725 and run it without bigger issues, you do not need to take action.

Core Health Sensor in Warning Status

The Core Health sensor shows a Warning status by default if PRTG was not updated within the last 90 days. The sensor channel Age of Code has a default upper warning limit of 7776000 seconds, which is 90 days. If the value is exceeded, the limit will apply and the sensor will show the warning limit message Please consider upgrading to the latest version to improve security and stability to remind you to regularly update your PRTG server.

The channel uses the build date of a PRTG version for calculation. Because of the issues with PRTG 19.3.51 we have no version online with a newer code base than the 19.2.50 release on May 15. The result is that the sensor shows a Warning status by default on currently running PRTG instances (starting on Tuesday, August 13). You do not have to worry and can ignore it.

If you want to turn off the warning and have a Core Health sensor in a green Up status, you can disable or change the default limit.

1. In your PRTG web interface, open the Core Health sensor that shows a Warning status.
2. Click the gear icon of the Age of Code channel to open the channel settings. See also PRTG Manual: Sensor Channel Settings.
3. In section Limits, choose the option Disable Limits to completely turn off limits for the channel.
   1. Alternative: Enter a higher value in the Upper Warning Limit field. For example, change 7776000 to 15552000 to get a warning message after 180 days.
4. Save the changes by clicking the Ok button.

The Core Health sensor will now be in the Up status again. Again, we apologize for the inconvenience these circumstances may cause you. We will release a new PRTG version as soon as possible. Update: PRTG 19.3.51.2830 is available for download since September 10.