this is solved
Link is broken.
Are you sure theres no other weird steam patching thing that you have on.
It has been a year since i uninstalled it, but i edited the thread and said that it now works, so it could have been an error.
There’s 2 solutions:
1- Restart your steam.
2- Right click on Gmod in steam then go in Properties, Local files then click on Verify Integrity of Game Cache.