I am having an issue since last night after the large server crashes of Xbox live on Wednesday. My friend and I used to run through the campaigns on coop without any issues. But now we cannot join each other in the lobby and play together. It will attempt to join and even show that I can kick him from my party even though he is not in the party. But it will give an error code for him saying the connection failed. When we reverse the roles, it is the same results. This is entirely frustrating and I cannot seem to find any solutions or posts from people reporting this recently. All the reports I have found are over one year old.