What's happening to Gmod?

I recently got a larger monitor with a higher resolution. However, I have switched back to my old monitor, and now something’s wrong with Garry’s Mod.

Whenever I start the game up, it freezes at the loading screen, and I can’t just turn my computer off, I have to unplug it. I’ve tried deleting Gmod and reinstalling it, but it hasn’t worked. I also tried asking people on Steam (as you can see here) but the solution I was given didn’t work either. What’s happened to it? Can I fix it?

Somebody please reply!

Try running it in windowed mode and post the crash dump files here.

To put it in windowed mode Open Steam, right click on gmod, properties, launch options, Type in “-windowed” without the "

In addition to what was mentioned above, try deleting the settings file that contains options about the resolution and such. This should cause it to remake this file with default 640x480 settings.