Here is an alternative approach, which uses an older backup copy of the database. However, this can only work if the backups are not corrupt themselves.
FAQ 17: Recover from a corrupt database
On Synology NAS machines, we have direct GUI access to the database area.
We can use File Station to recover if PMS was previously able to make database backups
Open Control Panel - Shared Folders - EDIT the Plex share
a. Permissions tab
b. Give your username R/W permission to the Plex share
[Screenshot from 2020-01-05 13-03-44]
Open File Station
Navigate to the databases folder
DSM 6: Plex / Library / Application Support / Plex Med…