Error while starting Minecraft

So me and my friend were just playing together then he gets the bright idea to make a loop command block that summons TNT. Then my game crashes. I relaunch and then I get an error saying, "Give it another try: If you keep seeing this, turn off your Xbox
by pressing and holding the power button for 10 seconds. Then turn it back on and try your action again. (0x80040200)." So I did that and I retried. Still doesn't work. I pulled the power plug then restarted it. Still doesn't work. I tried switching users.
Still doesn't work. There are two options: Close and Report a Problem. How should I deal with this?

:)

 

Disconnection from xbox live when starting minecraft

When starting minecraft i get disconnected from xbox live, and cannot reconnect while minecraft is playing. Is telling me i have to play offline

 

Halo 3 - Error while starting game

Have recently picked up a second hand Xbox 360 to play an old classic (Halo 3) but I am struggling to get it to work.

I originally picked up a digital download from Games for Gold but when I started the game I can only get as far as the menu. If I try to start a custom game when the screen goes black to start the game I get an error message that says 'Disk Read Error'.
I don't even have a disk at this point so that doesn't make much sense. After clearing the console cache a few times, re-downloading the game, doing a licence transfer etc I still couldn't get it to work.

I then picked up a physical disk copy of the game, formatted the hard drive and then for good measure removed the drive entirely. This essentially gives me a blank console, no profiles, no cache, nothing. I boot the game, try to load a map and I'm greeted
with the same error from the disk.

I can play any other game (MW2/Halo CE) without any issues at all, so it doesn't make a whole lot of sense. If anyone has any suggestions on where to go from here that would be great.