KODI says Your Library is currenty empty but the files are there

I did a clean LibreELEC install on my RPi B and added the links to my various files on my NAS and everything worked fine, as it did before I did the clean install. My movies and TV programs all seem to work ok.

I then updated to the latest LibreELEC Testbuilds for RaspberryPi (Kodi 18.0) and it works fine except

When I turn it on it show the main menu with all my links on the left hand side but the rest of the screen is blue with a notice saying

Your Library is currently empty. In order to populate it with your personal media, enter Files section, add a media source and configure it. After the source has been added and indexed you will be able to browse your library.

Also on the screen are buttons for “Enter Files Section” and “Remove this main menu item”

If I press the Enter Files Section button I can see all my files which then play ok.

Do you think this a KODI setup problem or a problem with the Test Build