Hi Daniel,
thank you for your answer.
As a test, I deleted the backup-job that caused the errors and created a new one with identic settings. The new job worked without errors.
So whatever the problem was, it could be easely solved.
I’ve just returned from a business trip and did not find the time to post my solution earlier.
Thank you very much. It is a very useful plugin.
I will support the developement by a donation.
Greetings from Germany.