For some reason, I've never been able to get User Startup Cheat files for work for me no matter what computer or version of the game I'm playing. Here's my setup with screenshots, in its current iteration. I've tried messing with capitalization, removing all references to moveobjects on, and various iterations of other cheats. Parts of it are copied from the Sims wiki tutorial. If anyone has any pointers, I'd really appreciate it.

As in the codes don't work?

You can use these two as direct cheats (without alias) :
boolProp allow45DegreeAngleOfRotation true (doesn't need to be turned off since you need to use the , . buttons for the angles - I've never found a reason to turn it off, anyway)
boolProp QuarterTilePlacementEnabled true (turns on/off with Ctrl+F)
Those would allow you to test if the cheat file works.

I can't see anything in particular. As long as you don't get an error code, the alias cheats are fine. If you get error codes when typing the alias correctly, something is wrong in the file.

The only thing I can think of is if you've copied it from somewhere that uses a different (but very similar) sign for the quote marks. You could try replacing them, just in case. The newer Notepad versions accept more writing styles when copied from the web, so occasionally you can get weirdness like this happening.

Okay, upon testing it with just the cheats, allow45degreeangleofrotation and setquartertileplacement, I can confirm they did not work. I think something must be wrong with the file itself, or the game just isn't reading it?

It's not setQuarterTilePlacement [true/false], you set it to [on/off]. If it's not an actual boolean property the values are on and off. If it is a boolean property, you have to specify boolprop.

The userStartup will often work down to where the problem is. Have you tried regenerating the file, or using one from a backup?

Do cheats work for you when typed in full format?

The "boolProp QuarterTilePlacementEnabled true/false" cheat can also be used as an alias (personally I prefer it as always on, since it's possible).

The "setQuarterTilePlacement" version does work as an alias, but not as always on (I used to have this one for a long while, mine was set to "on/off").

Tried regenerating the file (and by that, I mean make a new one from scratch), this time with just boolprop testingcheatsenabled, and still no dice. I don't have a backup, at least not one that's ever worked before. The cheats have always worked when typed in full format, and they still do currently.

With Testingcheats, can you shift-click items to get other options ingame? Do you get the black numbers showing in the right upper corner?

How do you type in the alias cheats?
You're aware you only need to type in the letters after "alias"?

Added an edited version of my userstartup file below (I removed some stuff that's related to a light mod and such). You can try if that one works.
https://simfileshare.net/download/4671458/

If it doesn't work, there's either something wrong with how the game is reading the cheat file, or how you're typing in the alias codes, and/or that you're using the wrong keys (for me I rotate items with , and . but different keyboards could have other buttons) or something like that.

Do you have file extensions hidden and perhaps the file is called userstartup.cheat.txt ? I noticed that your other files don't have extensions visible.

The type is listed as a CHEAT file, so that's really the extension. But I wonder if it's in the wrong Sims 2 folder, shouldn't actually be in The Sims 2 Ultimate Collection instead.

^ Depends on the game setup. If you have the UC, the folder is called "The Sims 2 Ultimate Collection (tm)", but if you have a different setup like for instance a disc version or non-UC collection of sorts (as in not the original UC or based on it), it's usually just called "The Sims 2".

Okay, thank you! Your user startup file is working in my game! I'm not getting black numbers to show up in the right upper corner, but all of the cheats are working, and the aliases work as well. Having added added a couple of my own cheats to the roster, it works fine as well.

I did actually have file extensions hidden, I didn't realize that. I wonder if perhaps because of that I was naming my file incorrectly, since I'd have to save my userstartup file as "UserStartup.cheat" and then I would have to type in "cheat" again because without file extensions visible I didn't realize it was already named correctly.

I think I removed testingcheats from the file - that's the one that causes the black numbers (it shows the game version, it's a way to know you're playing with the cheat on).

If you make one from scratch using a notepad file, it might not work. It's safest to use the file the game generates.

You shouldn't have to do anything else than save the file normally (as in file -> save, or Ctrl+S, or similar. You should not need to save as a new file, or rename it, or anything like that). The thumbnail will look like a notepad document if that's the program you associate it with, but it keeps the original file type/extension. It just shows which program is going to open the file.

If you make sure "type" (file type) in the folder view is turned on (have the view with dates and such open, right-click in the "name" column, tick "type" or find it under "more..." if it's not showing), you'll see the filetype even if you don't have the extensions showing. The cheat file should register as a "CHEAT" file under "type".