you tube and other videos won't play

[Android Central Question]

on my tab not only YouTube but also other videos won't play the videos which I recorded also don't play and even my camera won't work .when i open YouTube it says "unfortunately YouTube has stopped" and my recorded videos it says "sorry can't play this video" and camera it says"camera cant start " tell what to do i restarted my device cleared all cache ,data, of YouTube but still same prob .am worried now plz help