SO I'm trying to replay a hood and I had already saved backup copies of unused houses/sims I want to replay for whenever.

I have a house I built on this hood where I realized will become borked sooner or later. I never played any sims in that house, and I packaged it in-game anyway for safekeeping.

What I currently did is this:
I deleted my soon to be borked neighborhood (still have a backup of it just in case)
I added a new reset Desiderata Valley as per the instructions on this site.
I start the game to see that this house is not in the lots bin, but others are.
I exit the game and try to reinstall the packaged lot and get a message saying "This content requires Expansion Pack data that is not installed", which is weird because I have the Ultimate Collection. I checked to see if that lot is in the PackagedLot folder (it is). I also even reinstalled my soon to be borked hood to check on that house to see if I can get in and everything looks fine...

I'm not sure what I'm doing wrong...it's probably really simple, but I don't know.

Are you using the in-game installer to install? It can be flaky. You could use Clean Installer. I think it works with UC though I'm not entirely sure. There are several UC users here - doubtless they can tell you the details of how to get it to work.

Yeah, that is the default when I click on the package. I do have Clean Installer (I forgot, it's been a while!) but it can't seem to find that house file on my desktop...

I'm trying something now to see what works...maybe it's because I never actually sent that house I worked on to the lots bin in the first place? It should apparently show up for all hoods when it's put there, right?

Ah well, the thing I tried worked. I just went back to the sooner to be borker hood and added that house to the bin and it shows up for every hood Now I'm not sure I'm saving my packed lots correctly for future use...hmm. Thanks for your input, though!

Did you package your lot to file?
is the hood you packaged it from the same EP set up as the one you are moving it too. So is it coming from the UC to the UC? If you are playing on a different set such a store version, lots wont show.

So far I just hit the package lot button in the game and it saved to the usual location of PackagedLots I believe. I did that as soon as I finished building that house about a year ago and copied the file to my external hard drive for safe-keeping.

That's a good question! I'm not 100% sure, but I'm/pretty sure I built the house when I got UC since I didn't have to use my safekeep file til today (or so I thought)

You have two options when you package, to the old Sims 2 site, which won't save your lot anywhere as the site doesn't exist anymore and the second option to file, did you check you clicked the correct one?

Yes, definitely checked the right one.

I guess I'm just a little unsure because the saved package files have the little blank slate sim figure with a blue circle behind it and white backing behind that (if that makes sense?/even matters)
I thought the files were supposed to be saved as just having the sim figure and the blue circle (I'm just being paranoid now because I want to be sure if I ever have to reinstall everything I can place my saved lots/sims etc back into the game to play with again)

You need to right click on that package files and associate that file type to a new program and chose the Clean Installer and they will all open with it from now on.

Oh right, I knew that! So for future use that should definitely work now. Thanks!