I've had this issue as well. At first I thought it was because of all the artifacts and relics, that my Sim had in her inventory. But I also have it occurred in other saves - even after I pulled ALL my Selvadorada saves out and into a desktop folder.
How long has it been since you cleared out the cache files on your Sims4 game? It might not be the entire reason, but maybe part of the problem. To clean out the cache files, go to:
Documents > Electronic Arts > The Sims 4
Scroll down until you find the file:
localthumbcache.package
That's the cache files. Sometimes that gets corrupt and needs to be replaced.
Delete that file - a fresh new one will spawn when you start up again.
If that doesn't work -
Open your Origin panel and go to:
My Games Library
Right click on Sims4 and select "Repair"
Hope this helps you.
