Oh my bad, ok I got it, so Applied Energistics 2 was a config file.
I changed it to -1 and it seems to work for now.
I'll contact you if I get any errors in future.
First I'll try to fix it myself of course.
Thank you for your help.
I use Minecraft Technic Launcher to play minecraft and as soon I add the Flans Mod in, the game won't start anymore and I get this txt file in my crash-reports folder.
crash-2019-11-24_15.35.44-client.txt