Question
How to remove an SSL/TLS certificate from Plesk?
Answer
The steps differ for a certificate stored in a domain's repository, and one in the admin's repository (used by the panel on port 8443).
Note: Certificates can only be removed if they're not assigned to a domain, mail server, or any other objects/accounts.
Log in to Plesk
Deselect the certificate wherever it's being used
In Domains > example.com > Hosting & DNS > Hosting, set the certificate to Not selected
In Domains > example.com > Mail Settings, set the certificates for mail and webmail to Not selected
In Domains > example.com > SSL/TLS Certificates > Advanced Settings, select the certificate and hit the Remove button
Note: If there are issues, make sure the certificate is not used by any other services in the Used column
Log in to Plesk
Deselect the certificate from anywhere it's being used
In Tools & Settings > IP Addresses, open each IP address and make sure it's not selected, or choose another
In Tools & Settings > SSL/TLS Certificates, choose another certificate for Plesk and mail, and
Select a different certificate and press Make Default
Select the certificate and hit the Remove button
Note: If there are issues, make sure the certificate is not used by any other services in the Used column
