Very confusing title to fit a very confusing problem.

I had a homemade apartment lot with a sim living on it. I discovered that custom objects turned into basegame objects if visible from the outside while belonging to an NPC's apartment (like on balconies and in gardens), so I made the mistake of using the boolprop aptsublotspecifictoolsdisabled false cheat to edit away the ugliness, without having to move out my sim.

Then weird things started happening on the lot, so long-story-short, I eventually had to delete the lot and reinstall the pre-lived-in version with Sims2Pack Clean Installer, this time making the same edits BEFORE moving anyone in.

However, my game crashed every time I tried entering the lot.

I realised all the CC contained in the package file had installed straight into my downloads folder, creating a massive amount of duplicates, so after deleting those, I tried again.

Lot didn't crash anymore, but as soon as it had loaded, the furniture inside the apartment units gradually disappeared, the same way it does when NPC's moves into them... Given that there were no sims on the lot and I had just entered it in build mode, that was weird enough, but what made it even weirder was that it was a residential lot. I hadn't even MADE it an apartmentbase yet...

So I delete the apartment doors and re-enter the lot. Hooray, the furniture (and light) is back in the future apartment units. Everything seemed fine, so I put the doors back, changed it to apartmentbase and tried moving in my sim.

Then I notice that every single one of my neighbours is a young adult... ALL of them... It's like the game thinks it's an apartment lot, a residential lot AND a dorm lot all at once or something.

... Do anyone even know where to start? I spent years building and decorating this apartment lot, so I will never stop flippin' my shit for as long as I remain alive, if there is absolutely no saving it.

Sorry if the question seems too obvious, but are you sure you don't have any mods that change the way apartments are populated? Because those have been quite popular lately. Like "Townie apartment residents" by Cyjon.

First of all, you never need to reinstall lots. Once you've installed them, the original version is in your lot bin forever, if you ever need to delete it from where you placed it you can just replace it from the lot bin. Second of all, you never need to delete apartment lots if something goes wrong with the sublot. Just move your sims out and back in again, the sublot is deleted automatically once the sims move out.

Cyjon's random apartment residents mod causes YAs to be spawned as apartment neighbors, it's mostly harmless but there's a bug in Cyjon's original mod that can cause an error sometimes, that's the only problem. The game doesn't get confused and think apartment lots are dorms, and the doors used in dorms are completely different than the doors used in apartments.

The version in my bin was outdated and had only the basic build-structures and outside areas, so I unfortunately did need to install the version I'd packaged after I'd finished the lot completely back in the day.

... Wow. I actually do have that mod. Ironically, it's in my "corruption" mod folder, so I must've downloaded it, thinking it would help PREVENT problems in my neighbourhood. I still don't get why my neighbours have been normal all this time until now, though. I've been making families and moving them into various apartment lots for the past 2 weeks and there hasn't been any problems until about 4 days ago, where my game went apeshit despite me not having downloaded/installed anything new or made any changes to anything. This was just the most recent (and to me, most confusing) problem in the series.

Do either of you know how and why the apartment units became emptied while I was in build-mode on the apartment lot (not with a sim having moved in. Placed empty residential lot to be made an apartment lot later and entered it in build)?

If this is all written kinda strangely, it's cause I just woke up and can't even write in my own language properly yet, let alone any others :l

Edit: Update, I deleted that mod, restarted my game and moved my poor sim back in the lot again again again. The other apartments are still entirely populated by young adults.

Actually, nevermind any of this. I've been playing this game since its release and it just occured to me, that the head aches and time wasted has far exceeded my enjoyment at this point. This game is like a bad relationship I really need to just walk away from.

Thanks for trying to help.

I've had a few apartment lots I used to use that I've either had to modify to add parking and cars or abandon because the walk to work interaction was missing and recently found a Mod that restored the action and am working on fixing other issues to be able to return to the game.I would look at building something new and be more careful about how I remove things because some Mods can really mess things up if removed incorrectly from the game.
I had an issue with apartments getting neighbors being moved in and always getting into fights with each other in the halls and it made me feel like you until I found a Mod here that removed that from my game and left the empty apartment units empty until I manually move a neighbor in from the bin.The Mod is No Towmie Neighbors and I've had it in my game for years and it fixed the hallway fighting between residents once installed.