Game crashes after 3rd player joins

[Exeetor]

Me and two friends wanted to try the game out. When they had played for a while and I was about to join (as the 3rd player) the game just returns that the 3rd player is an "unkown player" and then both the connected players get dropped. Works fine with just two ppl. Same error on two diffrent hosts. Any1 else had this problem?

[sillyfly]

Some things that my help to find the problem:
1. Log files from the host connecting and from one already connected.
2. Network setup - are all of you in the same LAN? Maybe to are and a third isn't?
3. If you are not in a LAN, did all of you configure the port forwarding correctly? I seem to remember some port-juggling routers confusing Factorio...