Re: save game error: 403:8e5010b7:1d172885.
This error seems to be caused by outdated mods. But you mentioned not having mods in your previous post -
Sims 4 update broke game
https://answers.ea.com/t5/Technical-Issues-PC/sims-4-update-broke-game/m-p/7030182#M123288
Try clearing the 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/
As for your saves, you may need to rename save so the game can recognize it.
If you still have your saved games in your Sims 4\saves folder - [C:\Users\Username\Documents\Electronic Arts\The Sims 4\saves]
It may be the game isn't reading the save files correctly.
Have you tried renaming your saved game file? To rename your save, remove the version number. - .ver0 or .ver1 by deleting the .ver1 on the end.
For example:
Slot_00000002.save.ver1
Rename it to:
Slot_00000002.save
You may want to give it a different number if you already have a save 2 in your folder. The game should then recognize the save file again.
-- If you have an old auto save file (Slot_00000001.save) it's safe to delete as the game doesn't use it anymore.
If the above doesn't help, Crinrict has some very useful tips on saved games disappearing:
Save Games disappearing
https://sims4.crinrict.com/en/2014/09/save-games-disappearing/
