I couldn’t find this exact info anywhere, so I pieced it together from multiple support pages and trying things out until I got it to work. I’m putting this here in case I ever need it again, plus if anyone else ever needs it.
I have a PR4100, but would guess it’d be the same for all of the other WD My Cloud devices running OS5.
Here’s what to do to repair the Plex database:
Turn the Plex app off from the WD web GUI.
Log into the WD device’s SSH console using PuTTY (or whatever else floats your boat).
Go down to the root directory using cd … several times.
Run the following command (it’s broken into multiple lines here, but should be one long line in the PuTTY console -
"./mnt/HD/HD_a2/Nas_Prog/plexmediaserver/binaries/Plex SQLite" “/mnt/HD/HD_a2/Nas_Prog/plex_conf/Plex Media Server/Plug-in Support/Databases/com.plexapp.plugins.library.db” ".recover"
Turn the Plex app back on in the WD web GUI once the command finishes running (it can be quite a while, depending on how much you have in your Plex library).
