Hi Aurlyande
usually if certain lots don't load it's either something with the family or the lot.
Here's a guide that can help you narrow down a cause: 📓[GUIDE] Endless Loading | EA Forums - 5037259
It's usually a tedious work unfortunately.
LastExceptions can also help narrow down things so do you have any LastException files in Documents\Electronic Arts\The Sims 4 ?
- Delete the ones you have
- Trigger the error again
- Check if new ones are created
- If that is the case, please copy/paste the content here. You can open the file with any text editor.
*Deleting the file won't fix your issue. Posting the info is meant for troubleshooting.*