Can't go past the loading screen. Unavoidable crash.

For the past month, I've been unable to launch Sims 4 properly, and I can't understand what's wrong with it. I've tried many troubleshooting steps, including:

-Clean reinstall 
-Removal of all mods
-Clearing the "The Sims 4" folder in "Documents"
-Removing all saves
-Clearing Cache
-Driver updates
-Running as admin
-Verifying game files (steam/EAapp)
-Running the .exe directly
-dropping files from another pc installation

No matter what I do though, the game has absolutely no way of going past the first screen. It either crashes in a full white/black blinking screen before getting stuck and/or disappearing, or it stops working upon first user input. (mouseclick/keypress.) 

PC requirements are not the issue. It worked perfectly fine before.