My map freezes after some time without a Message Severity 3
Even without custom sides it does and I don't have any idea how this could happen.

that sounds like the map is to resourceintensive to me. check the things of which you have more than normally one by one and youll probably find the reason.

I have a lots smoke and fire effects in my map. If I understood you right I have to remove some.

yes, that could be it.

It works!

Thanks a lot!