I have set up my disk station again.
Now I try to reactivate the websites that are running on the DS.
I got some of them working again.
Now I wanted to call up a certificate for a website and get this message "The number of certificates issued by Let's Encrypt for your domain has reached the upper limit".
This website already had a certificate.
Is it possible to delete or reassign unused certificates?
You should wait until the rate limit has been raised (it's a limit of 5 duplicate certs in a sliding window of 7 days) and after that you should set up your setup permanently in a single go and don't re-setup again and again.