Game will not save and gets stuck loading.

This is happening to me too and I'm so frustrated because the only way to "fix" this is by moving houses but even then its only a matter of time until it hap peens again and I hate it because I decorate and personalize my houses. Glad to confirm that its not my mods.

I am having the same issue. I've tried saving mis game, saving and exiting, but it just spins and never saves

undecidedfloral lauren_dedmon Theslayersim83  Please test with no mods or custom content, as in, move the Mods folder to the desktop and delete localthumbcache.package.  You can use "save as" rather than "save" so you don't overwrite your progress.

Please also delete any lastexception files you see in Documents > Electronic Arts > The Sims 4.  When testing, if you can't load a household or travel, please look for a new lastexception.  If you find one, open it, delete its first line, and attach it to a reply here using the paper clip (Attachment) icon.

I went ahead and did two test runs. This one is from trying to resume game. 

This one was from trying to load game and play the household. 

undecidedfloral  Try adding this mod:

https://www.patreon.com/posts/mod-milestone-81237568

You should be able to remove it once you've successfully loaded the household and saved your progress.