Gmod won't load

I downloaded gmod on saturday, a few days ago, but it hasn’t opened since then. It starts up and goes to the loading screen, showing the character and the black loading bar in the bottom right corner. After a second though the screen goes black and the “hl2.exe is not working” box shows up. I have reinstalled steam, gmod, deleted the folders and reinstalled it everything. and another thing, when i reinstall it starts at 89%…Please help
And i have tf2 and that works fine so i have no idea

Garry probably broke it when he updated Garrys Mod. A lot of people including myself are having problems. Garry will fix it eventually.

i hope so this is really pissing me off