GMod reinstallation problem

Hi, I recently reinstalled gmod to fix some problems I was getting…It fixed it…but now I’m noticing something…Some textures aren’t showing up. They are just those purple/black boxes. I’ve noticed this on some guns I downloaded…Some other addons and such…I manually reinstalled all my addons but they still are looking weird…Any ideas?

Do you have CS:S mounted?

yes. anyone have any ideas?