My iPhone wont play any videos, why?

I tried to go onto the YouTube app, but EVERY video I click says, "Playback Error"! If I try it in Google Chrome, it either puts a cross through the play symbol, or it says "error"! Safari just crashes when I try to open the app. Is this because I deleted iapd.plist to fix my sound?

"Is this because I deleted iapd.plist "

Probably. The iapd.plist can affect several elements within the system.