Do you still have all your data in the “Plex” share? (Plex/Library/Application Support/Plex Media Server) ?
If you do, we can move it over.
If this is strictly a permissions problem (not seeing the media) the answer is SIMPLE.
Grant permission for System Internal User ‘PlexMediaServer’ instead of “Plex”/
DSM 7 forced the change.
Everything is documented here.
If you still want to wipe it all out, it’s very easy .
