@Mercellusive In case it's really that easy (sometimes it is), try clearing Origin's cache and then repairing the game: open your game library, right-click on the Sims 4 icon, and seelct Repair. Here's how to clear Origin's cache:
https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/
Since you haven't been able to play, it's probably not relevant, but if you have added mods or custom content, please move the entire Sims 4 folder out of Documents\Electronic Arts and onto your desktop. This gets everything out of the way at once. And if you've installed Reshade for Sims 4, please get rid of that too.
You mentioned trying to play in windowed mode, but how did you do that? There's a setting in GeForce Experience, which you can try, and there's also a way within Origin: open your game library, right-click on the Sims 4 icon, select Game Properties > Advanced Launch Options, and enter -w (with the - sign) in the command line box. When you do this, please shut down GFE first, so its settings don't have any effect.
If none of that helps, please try disabling your antivirus, at least long enough to test. It's often not enough anymore to simply set exceptions for Sims 4 and Origin.
@puzzlezaddict I've cleared Origin's cache and disabled my antivirus long enough for The Sims to work, and nothing.
I've been running it in windowed using the method you described, with -w in the game properties tab. I will try completely closing GFE and see how that works.
For now, the LE is still working just fine and I've had a great time playing so far.
