Why won't 2 player on xbox for minecraft work?

Me and my friend want to play minecraft together but it won't work. We will be loaded and everything but when I try to hit the start button on the controller it won't work. And it usually does. And my friend just used 2 player the other day.
(On the xbox 360)

To play the Xbox 360 version of minecraft, you need I think a 720p tv or above. If not that it is 1080p or above

You HAVE to have a HD TV and a HD cord to play 2 players. It kinda stinks that they made it that way