You nailed it, it was a corrupt database. I downgraded unraid to 6.7.7 successfully, but no luck in fixing the existing corrupt database. I tried the repair steps in https://support.plex.tv/articles/201100678-repair-a-corrupt-database/ but that didn't work.
So then I
Deleted the folder /mnt/user/appdata/PlexMediaServer/Library/Application Support/Plex Media Server/
Uninstalled the container
Re-installed it (binhex-plex via the CA)
But I still can't access the web UI, and it still shows a database issue. Note, the log location changed slightly, guessing I had slightly different settings when I installed it, not sure if it's helpful/relevant:
Old location: /mnt/user/appdata/PlexMediaServer/Library/Application Support/Plex Media Server/Logs/Plex Media Server.log
New location: /mnt/user/appdata/binhex-plexpass/Plex Media Server/Logs/Plex Media Server.log
Here's what the new log shows:
Jul 11, 2019 08:14:37.216 [0x147305e69700] INFO - Processor Intel(R) Core(TM) i3-4150 CPU @ 3.50GHz
Jul 11, 2019 08:14:37.216 [0x147305e69700] INFO - /usr/lib/plexmediaserver/Plex Media Server
Jul 11, 2019 08:14:37.216 [0x1473063532c0] DEBUG - BPQ: [Idle] -> [Starting]
Jul 11, 2019 08:14:37.234 [0x1473063532c0] DEBUG - FeatureManager: Using cached data for features list
Jul 11, 2019 08:14:37.234 [0x1473063532c0] DEBUG - Opening 20 database sessions to library (com.plexapp.plugins.library), SQLi
Lite 3.26.0, threadsafe=1
Jul 11, 2019 08:14:37.267 [0x1473063532c0] DEBUG - Running migrations. (EPG 0)
Jul 11, 2019 08:14:37.278 [0x1473063532c0] ERROR - SQLITE3:(nil), 11, database corruption at line 65066 of [bf8c1b2b7a]
Jul 11, 2019 08:14:37.278 [0x1473063532c0] ERROR - SQLITE3:(nil), 11, statement aborts at 10: [select max(max(metadata_items.c
.changed_at),max(metadata_items.resources_changed_at)) from metadata_items] database disk image is malformed
Jul 11, 2019 08:14:37.278 [0x1473063532c0] ERROR - Database corruption: sqlite3_statement_backend::loadOne: database disk imag
age is malformed
Any suggestions? Thank you!