What i wanted to add now after i posted and tried:
When i load it solo and do it, it crashes still. It didnt even gave me an option to invite him to the Game and he couldnt join either.
Then i also tried to do it solo, so i made a new game myself, got there but then it didnt crash. (Tried with Mods, and without mods)
It seemed to crash only in multiplayer.
Everything was out, Anti-virus everything.
Yes he could join when i created a new Game. We tried to load the latest save then again, and it crashed again.
We tried Arena and it worked.
Direct Connection also worked.
Also form direct File.
