Game constantly booting back to Main Menu with no Error Message

[TradeMarcTM]

I'm currently trying to help troubleshoot an issue my friend is having with the game. Every time we play after a few minutes it'll back him out to the Main Menu as if he was pressing Alt + Backspace. Any ideas to what this could be?

 

[Ryan]

Is it just backing him out, or is he getting an error message? What's the name of the character he plays on?