Everytime I want to join my friends' party, this message always showup! My friends also can't join me because of the same error! I can only join my friends through custom games! What is the problems? What should I do?
Same here. Tried everything. Upnp enabled. Nat Type 2. Nat Open on game. Doesn't make a difference. I can join any Public match regardless of NAT or Upnp, but can't connect with friends (Error unable to join game session).