There are so many questions from people having similar problems and almost none of them have been answered, but I can’t get the JoinSession node to work. It can definitely find the session but whenever it tries to join it fails immediately. I’m just testing it in standalone mode if that makes any difference.
It would be really nice if there was a way to get Unreal to say why it was failing.
In my game, I did it in another way. When my level is loaded, and my pawn ready, I created the session. And not create session, then load level. Try that one first.
I have menu system from which I’m running two instances of the game inside my editor. From the menu, one starts the server, and other joins. I am using online Steam sessions and online sessions plugin for this. And it works fine.
If you want someone to help you, you need to provide more information. This will bring you nowhere. Take a look at the logs, and you will have output why the join session failed. But I assume session is closed on level changed.
I think I never noticed the log before because it doesn’t show up as an error in red but it says
“LogOnlineSession: Warning: OSS: Player Anthonys-MacBook-Pro.blahblahblah is not part of session (GameSession)”
I was planning to do this game on Steam if it were to ever get finished but I think I’m in over my head with this whole multiplayer thing.
Thanks anyway.
Did you try what I said to load the level, and then create session?
You should not give up that easily. Making online multiplayer game is really hard, but achivable. If you are not experienced that much, maybe try something offline only, that is simpler a bit, and then move to online multiplayer.
After exploring the entire internet for two days, it turned out it was WARP vpn. I turned it off and tested, it works now. 
(i’m using ue4.27)
I stopped even trying for multiplayer. I was taking Bojan’s advice and just working on an offline version, and if I ever get this game to a playable point, then will I make the switch to multiplayer.
I will definitely look into that WARP when I do, unfortunately I will have to restart whatever multiplayer tutorials from scratch because I forgot all of it by now.
Thanks
