hello, if its okay with you, do you mind sharing how you were able to delete the zone object data and thumbnails to get your problem lots to work again?
Sure!
First I ask that you please make a BACKUP of your save file, just in case this does have any undesirable effects. This worked for me when a specific lot was crashing my game on loading, so bear in mind that if you are having a different problem, there's no guarantee this will resolve it.
Deleting Lot Data in Sims 4 Studio
Open your save in s4studio
A table should appear, click where it says "Type" to sort all files by type and then locate the Save Thumbnail files (they should all be grouped together).
This is the more annoying part, you now need to identify the problem lot using the thumbnails.
Once you've found the lot in question (there are two thumbnail files per lot so either will work) select it so that it is highlighted blue, and on the left hand side of the window where it says "Image" and "Data" select "Data".
Copy the code that appears in the box next to "Instance" and paste it into the search box at the top of the table, to the left of the "Clear" and "Filter" and press enter.
You should now be able to see Save Thumbnail 1, Save Thumbnail 2 and Zone Object Data.
Delete all three files, and then save the file. Please note that this essentially deletes the problem lot (it becomes an empty lot), and any TOOL'd objects in that zone area.
I hope this works for you too!
