I resolved it on mine by using a method from a similar problem previously discussed;
I did this;
Try this:
- Powered down PMS
- Used WinSCP to navigate to the folder /share/CACHEDEV1_DATA/.qpkg/PlexMediaServer/Library/Plex Media Server/Plug-in Support/Databases, renamed the com.plexapp.plugins.library.db as com.plexapp.plugins.library.db.backup (the other two files in the instructions from the above post were not in there so I didn’t do anything for those)
- Made backup of the latest db Backup (ie mine was com.plexapp.plugins.library.db-2019-11-13 - I just downloaded it to my laptop with WinSCP) and renamed that one com.plexapp.plugins.library.db
- Started PMS in the QNap App manager and left it for a while. Initially it had seemed to not work, but when I checked it half an hour later it was now working.
Hope that helps someone as the original has helped me…twice!