You might have a friends list that is way too big for the game to handle.
We discovered back then that the game's MP component doesn't appreciate friends lists that have more than 255 friends.
So in case the MP crashes immediately when trying to run it, try removing/blocking some people from your list then launch the game and try again.
(in case you're achievement hunting, block anyone that isn't farming with you, it'll be faster. But hey, you do you)