Seemingly out of the blue, I'm getting an access violation error. The game crashes on the loading screen before I can get to the hood chooser. Here's what I've tried:

Removing all CC and user files
Uninstalling and reinstalling the Origin Ultimate Collection version
Uninstalling the Origin version and installing Mr DJ's Ultimate Collection version
Using the 4GB patch
Using the graphics rule maker

All of these have resulted in the same exact crash at the same exact place every time. From what I've read elsewhere, this would suggest there is a problem with my graphics card now. Unfortunately, I am absolutely useless when it comes to graphics cards and related things. I've included my DxDiag file and the crash log in the attachments. Any help wold be appreciated!

"System memory: 1024 Megabytes total, 1024 Megabytes free."

Your game is most likely running low on memory because it's set up wrong. Check if the 4GB patch has been properly applied

the "COMPUTERNAME-config-log" file in Logs should ideally say
Memory: 4096MB
Free memory: 4096MB
and texture memory should not say 32 MB but a higher number (depends on settings).

If you've installed the game on the C: drive, and the 4GB patch isn't applying properly, find your highest EP EXE file (or M&G), copy this file to the desktop, run the patch on the EXE there, and move/replace the file in the original folder. You'll get an Admin prompt, click Yes to replacing the file.

The texture memory can be set up with Graphic Rules Maker. It's the "Display Memory" number from the DxDiag. You can also do it manually, like so: http://www.leefish.nl/mybb/showthread.php?tid=7909

I checked that config log, and the memory/free memory lines say 1024 MB instead of 4096 MB. Looks like the 4GB patch is not applying itself for some reason. Even when I applied the patch to the .exe on the desktop and recopied it back into the correct folder, it still has 1024 MB there and crashes. Weird. Is there a different way to set the memory to the correct amount?

Did you apply the patch to the M&G EXE? (Sims2EP9.exe)

What were your settings in Graphic Rules Maker? Are you sure those settings applied properly? If installed on the C drive, the same issue with Admin access could be causing issues there. You can try saving a copy of the finished files on the desktop, and manually replacing them.

Can you attach the config log?

Ok, good news, I got things working again. When I went to go check on the Sims2EP9.exe file as you directed, I had a sudden suspicion that Origin was causing the issue. Origin booted itself up every time I went to play the game, so maybe it was "updating" (i.e. reverting back) the .exe every time I tried to launch the game. I downloaded a no CD/Origin crack (George) and placed it in the files, and now everything is fine.

I appreciate your help!