Digital signature problems in Adobe Reader

Hello,

One of our customer uses internal Digital signatures.

The problem is, that signing a .pdf document via Adobe Reader randomly fails.

The users have to try 10 times, before it works. Sometimes, it works on the first attempt. Also, sometimes no errors, but the signatures are not added to the documents. Sometimes, there are errors, but the documents are signed.

It can work 3 days without problems and then, again this random errors. They have these problems locally and also with document based on shares.

I've tried to disable automatic update of Adobe Reader, but it didn't solve the problem. I've added the signature in the Trusted Identities, it doesn't solve it either.

Have you already seen this behavior?

I've tried to troubleshoot, without success...

Waiting for your tips... Thanks in advance.

Best regards

Tony