Ok Sorry, I restarted the game several times since that bug occured. I found that alt+f4 is faster to exit a frozen server than by the menu

Sorry I did formulate this wrong. The game got a super lag (freeze) and I decided to exit via the menu. This took some minutes but the game did not crash.
I dont know if there is a log file if the game did not crash.

But this screenshot shows other servers that have more players in them than they ...

The player limit seems not limiting the amount of players that can join.
I created a public server with limit of 3 people but many more joined till the game crashed.