Can't Access Mulitplayer

Just the other night I was playing a Arena game and during the game it seemed to have switched hosts and/or I was dropped from the game, since then from the main menu when I click on any of the options under Multiplayer except Theater I can’t access them?! Has this problem happened to anyone else?! But I am still able to play Single Player just fine.

Have you tried hard resetting your console? Hold the power button in for 30 seconds, unplug your power brick for a bit and plug back in, then turn back on and load up Halo. It should hopefully work after that