Crashing when launching

Tonight I sat down to launch Garry’s Mod

It crashed when I opened it

I have no changed anything since yesterday when I was able to play

steps taken so far -

redownloading various executable
redownloading parts of gmod
reinstalling garry’s mod from scratch
-dxlevel 80 (and others)
shitload of virus scans
restarting steam
unsubscribed from all workshop addons

I can’t launch a brand new install of Garry’s Mod. Dafuq.

Anyone have any ideas?

Solved this issue by verifying the integrity of all my source-based games.