I'm having this problem with some lots but not all. So I placed a gallery lot, changed many things about it, and tried to re-upload it to my library (I only upload for myself only) and it wouldn't work. I don't use mods or cc, but the lot did have paintings from the og gallery lot. Do you think that's my issue? I also tried the trick where you wait on the error screen for 5 minutes before clicking OK but it still didn't save. I was able to use a shell challenge from the gallery, build it out and save that, so it's probably something on that other lot.
It's not your issue, because I've been experiencing that for over a year, it's extremely frustrating.
The Sims Team
