After updating to PRTG 26.1.118, the PRTG core server does not start anymore, and the log contains the following message:
Signature of \Program Files(x86)\PRTG Network Monitor\32 bit\PRTG Server.exe is not valid
What can I do to resolve the issue?
This article applies as of PRTG 26.1.118
New Root and Intermediate Certificates in PRTG
As of PRTG 26.1.118, Paessler signs PRTG binaries with a new EV (extended validation) code signing certificate. This replaces the previous OV (organization validated) certificate. The change requires a new intermediate and root certificate authority (CA).
Systems that do not have the new certificates in the Windows certificate store cannot verify the signature of the PRTG binary.
This causes the PRTG core server to not start in some cases. The respective error message in the log file is:
Signature of \Program Files(x86)\PRTG Network Monitor\32 bit\PRTG Server.exe is not valid
Affected versions
You are affected if you run one of the following versions and plan to update to PRTG 26.1.118:
- Stable: PRTG versions earlier than 26.1.116.1532
- Preview: PRTG versions earlier than 26.1.116.1534
Solution
Add the new trusted certificates (root and intermediate). You can either use the Microsoft Root Certificate Program or download the Entrust certificates from the SSL.com repository.
Microsoft Root Certificate Program
To use the Microsoft Root Certificate Program to add the certificates, follow the instructions here: List of Trusted Root Certificates in Windows.
Download from the SSL.com repository:
Download the following certificates and import them to the Windows certificate store on the PRTG core server system and probe system:
