I disabled custom content (when you get the dialog when you load the game, asking if you want it disabled or enabled) by mistake a few days ago and when I realized what was wrong and re-enabled them, I got the warning from the SuperDuperHugTest that one of my lots was infected with the bug. I have the Test and BO's No Sim Loaded installed, but is my game still infected? And if so, would removing the folder in my documents and generating a new one help, or do I need to do a full reinstall?

The test file should be able to remove it from your lot(s) completely. If it doesn't, you can use Chris Hatch's Lot Cleaner to remove it as well. Since you probably have mods that cause it, it shouldn't matter anyway unless you share lots. If you share them, just load them in a clean Sims 2 folder and run the SDH test again to remove it.

Ah, okay! But should I make a clean folder just in case? (I'm not too attached to my current neighborhoods/lots, since I just reinstalled the game recently, so it wouldn't be too big of a deal)

It's already removed- as soon as the SuperDuperHugTest gives you the message, you click okay (as many times as required) and save, it's gone from that lot. You just need to do it for each lot that's infected (but if you leave the SuperDuperHugTest in-game then you can find these lots as you play).

Alright, thanks to both of you for your help!

Also do remember this code is part of the game, it's code for modders, it just shouldn't be live in your hood is all. It's not harmful to anything, just an annoyance.