Multiplayer shootout does not work with 4.8

So why is it that I get error of, no main menu could be found? I’m trying to test my menu system with multiplayer, so starting one window when playing offline really doesn’t help. I will try work around again to see if I can get it to work. Will this happen in a build of game? Also why do I get bloom from server showing up in client window? Sorry for all questions and thanks for help.