Problem with Resident Evil 5

Hey guys, I have a problem with resident evil 5. Whenever I try to play a coop game, I get told that there was a communication error and my connection is lost. This results in my having to play the game solo with the brain dead ai. Please how can I fix this?

it's your connection most likely. I have a tip for you though. Give the AI Sheva machine guns and rifles. She uses the machine guns well and snipes out a lot of distant enimies. Keep the shotgun for your self and all the pistol ammo. Use the pistol as much as possible. You can also give Sheva health items becausse she will heal you when you are low on health and you can also use her for extra storage.

online doesn't work for mercenaries either, can anyone help me?

Works for me, just be your connection or your game.

Maybe it is your connection that could be it.

I have an even worse problem with the game! I beat it with a friend last night on co-op, but he got credit for beating the game but I didn't The game did that to us once before, and we had to redo a level. There's no way in hell I'm going through that annoying last boss fight alone.

i have that same problem soph i just beat 5-3 tonight but it didnt give me the achivement so tomorow i hav to beat it again i dont want to face that boss again its happened on 2 other acasions they need to fix this problem