Have you used mods or custom content previously at any point? If so, you may need to clear your cache files and restart the game. Its important to do this step frequently, especially when updating mods/custom content, or removing them entirely from your game.
Have you also checked your mods folder? You can find it by following this path:
C:\Users\PC Name\Documents\Electronic Arts\The Sims 4\Mods
If there's anything in the folder, you can delete it. It's safe to delete the Resource.cfg file too.
It may also help to ensure that your mods/custom content options are disabled in your game settings, if they aren't already. Hope this helps!
No. I'm a totally vanilla player: no mods or cc at all. I don't even download anything off the public gallery if it has either. I know this household is 100% mod and cc free because I created the adult sim myself and his twins are the result of an alien pregnancy, so that's all BG driven to begin with.
It's possible for some gallery content to contain mods or custom content, but not flag up when it's uploaded. For example, I use a mod that increases the number of facial presets in CAS, but my sims don't get flagged as modded when I upload them.
Did you try uploading your household again after doing the steps I mentioned? What was the result?
It's also worth mentioning that even if your content is flagged as modded (whether correctly, or incorrectly) it doesn't mean you'll lose that content. You just need to check the "Include Custom Content" option and anything with the blue wrench icon will show up. It just won't show up by default, unless you have that option checked.
So I have followed all your suggestions, as well as performed a complete restart on my computer once I had finished, before restarting TS4.
This time I did not receive that 'error' message and CAS appeared to show that this family was properly updated. However, when I opened the gallery itself, the family didn't appear; neither in my library, nor in the public gallery where I also tried to upload it. 😢 I am open to any other suggestions you may have, but I am becoming resigned to the possibility of losing this family forever.
