Sooo....

I had some saved lots from an older neighbourhood as sims2pack files.
I placed them in my previous neighbourhood in my previous game installation and the CC they contained showed up just fine.
I packaged my favourite lots from that neighbourhood.
I reinstalled Sims 2 UC with fresh, clean templates.
I removed traces of Sim stuff from all the packaged lots in SimPe.
I made a new custom neighbourhood.
I installed both the oldest and newest packaged lots using the Clean Installer (as well as the CC, even though it was all already in my downloads folder, cause the CC didn't show up for any of them if I only installed the lots).

The strange thing is that the lots I built in my previous neighbourhood work just fine. The CC shows up without issues.
The lots from the neighbourhoods I had before that though and a lot I downloaded, only show up (or rather, the CC they contain only shows up) if said CC is allowed to be installed from the package files directly into the main downloads folder AND STAYS THERE.
Well, actually a single one of the old lots doesn't have the problem. The CC in that one shows up just fine, like with my recently-packaged lots. I can't think of any red thread between the ones that work and the ones that don't.

All required CC already exists in my Downloads folder, sorted neatly into subfolders. It just doesn't show up in those particular lots, unless it's all vomited in its random mish-mash'ness into the Downloads folder itself.
I've tried removing the "affected" lots and replacing them from the lot bin, but it makes no difference.
I have no reason to think deleting them from the bin and reinstalling only the lot would fix it as that didn't work the first time, despite me having all the required CC for them (as explained above).
And if I re-installed all the CC along with them, I'd be back to my current problem of having a ton of duplicate meshes and unsorted CC in my main Downloads folder, that I'm unable to move or delete.

I have never in my life had my lots' ability to recognize CC depend on whether or not it's in a subfolder and it wasn't the case when I packaged them from my previous hood/game. Do anyone know what I might have done wrong and how to fix it?

I bet it's something really simple and basic, that'll make me facepalm.

First picture shows a lot made in my previous 'hood with all-working CC. The second shows a lot from the 'hood before my previous 'hood (which was still also placed in said previous hood, though) with a lot of... vases in it.




Edit: The primary problem apparently wasn't that the CC was in a Downloads subfolder per say, but rather the name of it (Lots). I changed the folder name to "Lots CC" and now everything shows up. Don't do that, apparently. :l