My BB Playbook is showing all media files are gone (picutres, music and videos) although I can see them in the folder structure when connected to PC through USB. Recent youtube videos also completely empty. All the Apps are still coming up on the playbook. I’ve tried the “hard reset”

I am a noob, but I been looking for a solution to my problem on the Net for quite a while, and can’t seem to find an answer that would solve my situation.