Sanza Disc help

MP3 players Sansa Fuze
1

Hi
We have an old 8gig sanza fuze, always worked great. Problem now is all the folders are showing empty. Plug it in to the pc and they are there & you can play them on the PC. Unplug the fuze & it shows empty every folder. Tried rebooting the fuze but still nothing. Can anyone help please
regards
Jo