DB upgrade error from 20.0.11.1 --> 21.0.3

Hi All,

I have an error when the update finishes looking like this:

Repair info: Change row format for oc_comments_read_markers …

Doctrine\DBAL\Exception\DriverException: An exception occurred while executing a query: SQLSTATE[HY000]: General error: 1025 Error on rename of './nextcloud/oc_comments_read_markers' to './nextcloud/#sql-backup-54a-3f08' (errno: 168 "Unknown (generic) error from engine")

I made a dump from the database before doing this. However I seem to have some issues with PHP and Phpmyadmin is not behaving as it is supposed to…

I’m wondering if any crucial database changes have been made, preventing me from reverting back to the 20.0.11.1 installation and trying my luck another time.

Or is this just going to result in database corruption?

I could try to restore the DB from the CMD but no experience in doing so. I don’t want to delete the existing DB and then ending up stranded. Tried to duplicate the existing DB as backup but no luck so far…

Thx for any advice!