This error pops up when i try certain features.

http://prntscr.com/75wkam

Thats the error, it does it with some things or will randomly just do it, i am on windows 7 and thinking about installing windows 8.1 again.

Dont know if that will make a difference, if anyone knows how to fix this error please tell me. thanks

I think it's bug. I have sometimes same thing too, but very rarely.
Ex. I try to set up car weapons, it sometimes crashes.

That means the mod menu has crashed. This is caused by spawning in too many items at once etc. refrain from doing so.