UTAH not loading

If I start UTAH it will not load and sometimes my PC is crashing :C All other maps work well

PC Stats: CPU: AMD A8-3820
Mainboard: MEDION MS-7748
Memory: 4GB DDR3
Graphics: AMD Radeon HD 6550D

I know it isn't a good PC but all other maps will load and i can play them (with very low FPS :C)

I already have reinstalled BeamNG.drive and i tried it with, and without mods

PLEASE HELP!

THANKS!