I have just tried starting your game - after two hours play of the single player campaign, i cannot save.
Game returns "There is not enough storage space on this device. Do you want to select another" as the message.
I have 212GB free on my XBox 360???
What is the issue here? I have installed this game on my console, and retried several times at several separate stages. There is no support on the halo4 website for this, no-one replies.