Garry's Mod not starting

Everytime I try to start it, it gives me an Engine Error saying “[Steam] SteamApps() Is NULL” Can someone please help me understand how to fix it?

restart Steam

Having same problem, tried restarting steam but still not working.

Uninstall GMod?

Verify game cache?

Remove windows?
Install linux?

Well, was same problem, steam reinstall helped.

I have literally the same problem. Reinstalling GMod or Steam doesn’t work, verifying cache doesn’t, either defragging, etc. At this point I feel like reinstalling Windows…

First, quit Steam. Make sure that the process isn’t running after you quit.
Then, restart Steam.