All I did was dissect Multiplayer Shootout project which is setup for Steam right now, and I also followed 's Steam tutorial on wiki.
I made a brand new project and pieced it together and I also did some bugfixing from Multiplayer Shootout, workflow in BP wasn’t that clean.
It works perfectly for me, I can create sessions and join them, tested on 3 different computers with 3 different Steam accounts and their Steam usernames show up in my scoreboard.
I’m just wondering why Shipping Build requires a steam_appid.txt. I thought that was already included. development build doesn’t need it.