Hello, Me and 3 mates are attempting to play 4player co-op Zombies, problem is whenever the 4th person accepts the invite one of the previous 3 in the lobby (that arent hosting) drop out of the lobby and cant rejoin. We tried defragging game cache all of us and verifying integrity of game files. We also tried making open games for friends only, all of us tried hosting and inviting. All of our routers are open for NAT etc, no problem with other games. Any ideas? -awok3N
