Almost evey map I go into the maps are purple and black squares and there a lot of errors, help?
That’s missing textures, I think.
Mostly every one I go to except Flatgrass and Construt.
Do you own Counter Strike:Source?
I can’t help you if I don’t know which maps are doing this. I know the purple and black checkerboards mean missing textures, and the big red ERROR means missing models. It means you don’t have the game with the content used for the map installed.
He probably got Gmod in the half price weekend, and he most likely doesnt own CS:S.
Indeed you definitely need to get CS:S because a lot of Gmods content (user created) needs CS:S for textures and models.