Recently some of our customers, that upgraded to the latest version of PRTG, have reported that our sensors stopped functioning right after the upgrade. Below is an article that explains the issue and how to mitigate it.
Detailed description
Upgrade to latest version of PRTG (20.x), may cause the AutoMonX sensors to stop functioning.
Symptoms
Usually, following the upgrade, the error message of our sensors in PRTG is as seen below:
"The DNS server does not respond. To resolve this issue, check if the DNS service on the remote host may be shut down..... (code PE002)"
The root cause of this issue is renaming of some of the AutoMonX sensor files with the .dll (Dynamic link library) and .exe extensions that happened during the upgrade of PRTG to .dll.old or exe.old thus causing the sensors to stop functioning.
Mitigation:
Rename any dll (Dynamic link library) that were renamed to dll.old or exe.old during the upgrade to their original name: .dll or .exe. No reboot / restart of probes is required.