Unable to shade polygon normals

I can’t start Gmod and I’m getting the error “Unable to shade polygon normals(76561197960279927)” could someone please help!

(User was permabanned for this post ("Stole Gmod" - verynicelady))

Validate gmod files. if that don’t work, try validating TF2 as well.

I fell for it and looked up the id


[editline]5th October 2014[/editline]

LOL he pirated a $10 game. GG

no he really didn’t, look up that id it’s garrys…