NUC target: Music player not showing music songs

When I start/boot the target system the first time, no available songs in the player app are shown as if they don't exist.

Music files are in the file system, log also shows that they are somehow processed.

I couldn't find the error myself, log is attached if it helps

(actually this error is not due to possible latest changes, but is existent for at least more than 1 week)