@1luhsaffDid you try to enter your family on the world map and then you got this report? Or maybe it happened during the trip?
This error is caused by attempting to load an object in the game that has broken references. Unfortunately in your report, there is no named mod that could cause it.
I can only suggest that you look for this mod or CC.- if mod caused this problem, not a game bug
1. Move the mods folder to the desktop.
2. Find and delete localthumbcache.package file in the game folder. Delete also all folders with the word "cache" in the name.
3. Fix the game in Origin.
Origin/Library - right-click on TS4 - option "Repair game"
You have to wait until Origin will fix all packs, not only the base game.
4. Turn on the game to create a new, empty mods folder and check if the game is working now properly without mods
5. Check if there are new updated versions of the mods and CC you are using.
List of broken mods and CC after the last game updates
https://forums.thesims.com/en_US/discussion/976565/broken-updated-mods-cc-june-20-eco-lifestyle-patch6. Then copy from desktop your mods and CC and paste it in the new mods folder. First, paste script mods one by one every time checking if the game is OK.
Do the same with CC but if you have a lot of this, try the 50/50 method. (Divide your CC into smaller batches for example 50 pieces in one subfolder and check these subfolders one by one)