Thank you very much!
I looked into the files of the game and there was the testing mode in the mod folder. I have no idea how it remained there after reinstalling the game, but after deleting the mod the game starts normally.

I haven,t installed any mods. The error appeared right after I installed the game and started it.

Everytime I try to start the game on version 0.9.8 I get the following message:
Error while loading prototype "mjollnir": No such node (usage_priority)
I havve absolutely no idea how i could solve this problem and need help.

Thank you for that hint.
Dut I think an option in the world generator screen would make it much easier, because you don't have to to create your own world in the editor every time you start a new map.

I think very rare fields with endless ressources would be great. And it should be able to deactivate this feature for people who don't want this.