Thank you for your answer. But I do not understand it fully. I am not talking about AI racing (don't know how to setup a server for that). I am talking about online racing with other people.
For that online race I have created an entry_list.ini with 30 cars (because the ui.json states that the track has 30 pits).
But that does causing Crashes when clients try to connect.
When I reduce the entry_list.ini to 25 cars, everything works well. So maybe just the ui.json is wrong?
Regards