I was actually getting this when I first played the game. The exact same thing. Download both game discs to your hard drive, that fixed it for me.
I've never tried to do this before, where can I do this from?
Er I mean install I guess. But put the first disc in and go to the dashboard and where it says play Halo 4 press X for game details, then it should say install. For the second disc just put it in and load it up.