[0.11.21][Multiplayer]Certain players unable to join!

[provet]

Vanilla 0.11.21

I dont know how to describe this other than what we did:

Player1(P1) OS: Win 7
Player2 OS: Win 7
Player3 OS: Win 8

Tried scenarios:
P1 host, P2 joins, and it works with no issue. P3 tries to join but drops out which also causes P2 to drop.
P1 host, different joining order, same result, both drops
P2 Host, P1 joins with no issue, P3 tries, both drop
P2 host, P3 tries to join but drops, P1 joins successfully.

The day after P2 and P3 tried again (P2 hosting) With the same error, here's the Log file

[kovarex]

Hello.

There have been a lot of changes and fixes of the multiplayer logic, so it might be fixed in 0.12.

It can also be a problem, when 2 of the players are behind the same nat, as in this topic: https://forums.factorio.com/forum/vie ... =7&t=13646