Gmod not working

Whenever I start a source game, a message appears saying: “The instruction at “0x11b1cbbd” referenced memory at “0x0f131454”. BTW this happens for Gmod mostly. I can at least play a little with Counter Strike: Source, but with Gmod, I select a weapon or prop, and 5 seconds later that message appears. Please leave posts HELPING ME, not dumb ones like " I have the same problem” or “I don’t know what to do”.

Did you try reinstalling Gmod and/or CSS?

Are you running a Intel GMA?
Did you purchase the Orange box?
Tried these 2 commands
sv_cheats 1
R_drawparticles 0

I reinstalled everything, I don’t have the Orange box, and on the commands do you mean on the console of Gmod? I read of someone having the same problem, and when he got HL2, he played his Source games with no problems.

Should I reinstall Steam completely, because reinstalling Gmod doesn’t work?

Edit: Gmod is working now. Thanks for the help.