There’s actually a problem in the game : the friendlist doesn’t work properly and we can’t see anyone online (being with them on voip, they are online and have the same problems).
Therefore i can’t figure out a way to invite my friends to play.
I have the same issue, we have 3 people in our house trying to play together, it shows 2 of us as online and the other as offline. When we try and invite each other to a party the accept box comes up but clicking it does nothing for the 2 that show online.