Addons sappin mah game.

So, for a while my Gmod was not saving and I could only run it once every time I used my computer.
I got an error say Gmod was already running. So, I cleaned. I found out that what seems to cause this is addons that don’t go in the addons folder. IE. Gamemodes, older ones that install directly to materials/models folder. Does anyone else have this problem? Or know how to fix it?

Addons that install to the addons file still work fine, and Maps don’t cause problems.

Then manually drag em into the correct folder.