Im seeing repeated instances of the library view being empty. I've had this before many months again and ended up having to rebuild my whole database from scratch because the backup was pretty old.
(Still no way to automate the backup system )

For clarity here... the LIBRARY isnt empty - I just cant see it. The window where it should be is empty. I can stream files from it - but obviously as the library window is empty I cant actually do anything such as edit or create playlists.

It happened again earlier in the week. I sorta got it working again by:
backing up the database
uninstall
reboot
reinstall
restored the database.

All seemed well. But its just done it again.
I have been having some issues with a USB hub failing in the machine, but I wouldn't have expected this to render the library pane empty.