I'm using generic LE12 nightlies.
The newer versions are not able to create a working SQL database anymore.
During the first boot the SQL database "myvideos124" is created.
Files from the videofolders can be scraped (local information only), but the library is not populating.
Issue can be solved by reverting back to an older nightly from December 11th, deleting the SQL database myvideos124, restart Libereelec to let it create a new SQL database "myvideos124"
Now videofolders are scraped and the library is populating normally.
The outdated version can now be updated to the actual nightly. Once the sql database is created by an older version it keeps working with the actual versions.
I cannot say, if the version from december 11th is the last working version. I just grabbed this for testing.
My observation:
SQL database created by actual nightlies has 32 rows -> non working
SQL database created by december 11th nightly has 39 rows -> working
SQL database created by an actual windows Kodi nightly has 39 rows -> working (however these version is already using myvideos125).
Not sure, if this report is helpfull.
At least it might be a usable workaround for users observing the same issue.