Sims 4 won't save to my library

@TossJM

If you've recently tested your mods and custom content to make sure they're up to date with the latest game patch - August 16 2018.
https://help.ea.com/en-us/help/the-sims/the-sims-4/the-sims-4-updates/

You may need to clear your game cache and delete the localthumbcache.package from the Sims 4 folder to help with troubleshooting.

How to Delete Cache Files
https://sims4.crinrict.com/en/2014/09/delete-cache-files/

Thanks for responding. 🙂 

Yeah, I've tried all that. No fix. I removed all my mods & cc, & immediately after, cleared my game cache and deleted localthumbcache.package. There's only one family that shows up, & it's an older version of them that still shows a picture of them with CC, although the current family version I try to save has no CC. None of my other families save at all. I'm my wit's end here. 

@TossJM

You can try resetting your your user folder by renaming it or moving it to the desktop and playing the game so it makes a new Sims 4 folder. Here's a how-to:

Sims 4 Factory Reset - Rename your Sims 4 folder to Sims 4-Old. The game will create a new folder next time you play.

- Renaming it or moving it to the desktop will help you have a backup and keep your Sims 4 files safe.

Repair the Sims 4 game. In Origin > Game Library - right-click on Sims 4 and select Repair.

Try playing the game, this will create a new Sims 4 folder. Try playing a new save. Does it play okay, then start putting files back.

If it's still having issues, do not save it.

Here is the list of files and folders to put back:

- Options.ini (User game settings)
- Tray Folder (Sims/Houses/Commercial lots and rooms)
- Screenshots/Videos/Custom music
- Rest of the save games, if any.
(leave out slot_00000001.save which is the autosave. It is not used anymore.)
- Custom content like clothing, hair, skins, and makeup
- Mods (Put these back one by one to make sure they all still work)

Custom content can become outdated with most new game patches. If the game works when the Mods folder is removed, then one or more of the mods and/or custom content has become outdated and will need to be removed or replaced. EA/Maxis aren't responsible for broken mods/cc. It's up to the creators to fix.

Try the 50/50 method:

1. Move all the mods and cc out into a temporary folder on the desktop.
2. Move a few files back at a time. Load the game to make sure it loads and everything is good.
3. Delete the localthumbcache.package from the Sims 4 folder.
4. Repeat steps 1 - 3 till there is no more files to check.

** While your testing, don't save the game. If you find any problems, delete the mod or custom content file.

How To Find Problem Mods and CC
http://simswiki.info/wiki.php?title=Game_Help:TS4_Finding_Problem_Custom_Content

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More information - Resetting the game to factory settings without reinstalling
https://answers.ea.com/t5/Technical-Issues-PC/READ-FIRST-Troubleshooting-your-Game/m-p/3621199#Resetting

If you move or rename the Sims 4 folder, the game will no longer be able to find it. When you go to play the game it will create a new folder.