Error processing certificate created by...the signature on the certificate was found to be invalid

Since upgrading the Domino servers from 6.5.2 to 7.0.2, each attempt to access the server results in this kind of log entry:

“Error processing certificate created by /Organisation for /Unit/Organisation: The signature on the certificate was found to be invalid. Check the log file for details.”

The interesting part: the users can access the servers, no further problems reported. Only the log gets spammed.

Any idea what is causing this behaviour?

Subject: Error processing certificate created by…the signature on the certificate was found to be invalid.

Hi, I’m getting the same messages in my console.

03/05/2007 10:48:54 AM Error processing certificate created by /OU/OU/O for User: The signature on the certificate was found to be invalid. Check the log file for details.

I recently upgrade my server from 6.5.4 to 7.0.2. Can anyone help me??