Password change is disabled because the master key is disabled”

I currently have Nexcloud 20.0.14 installed at a web hoster. On the server I have no root access. I can administrate the db with myphpadmin.

I have upgraded the MySql database from 5.7 to version 8 from the web host.

Since then I get the error “Changing the password is disabled because the master key is disabled”.

Unfortunately none of the solutions I found work. The master key cannot be activated as described in the instructions.

An occ encryption:enable-master-key ends with an [object Object].

How can I enable changing passwords again?