@MoeMoe Iv had this problem all week but got it going again so try this.
Delete the Update folder & common folder.
Verify the integrity of Files through steam,then it will download them (bout 36gigs)
Once done turn game on & it should start to run as normal. but make you will have to replace tose 2 folders in your mod folder if your modding.I had to re mod my game agin but no biggy. Once it starts to run normal again (if so) exit the game & check your Launcher file through Documents to see if there is any other CUNTY ERRORS!!
Good Luck bro