How do I remove files downloaded from servers?

There’s this one build server I joined, and whenever I finish downloading the files and play, everything is fine. Then when I go to a different server or play singleplayer, I get a bunch of wire errors I’ve never gotten before. Whatever it was also removed my weapons when I spawn. I’ve reinstalled Garry’s Mod and then tried joining server again, all it did was the same thing. It didn’t happen to my friend though. Is there a way to delete files downloaded from servers?

Its probably not a download error. It could just be how the server installed wire.