maylin333 Does this happen with no mods or custom content present? Please move or rename the Mods folder and test. You can use "save as" so you don't overwrite your main save.
Your C drive is also very low on free space. It's not critical yet in terms of basic Windows functions, but it could be having an effect on Sims 4, especially if OneDrive is also running on your computer. OneDrive could be trying to push data to cloud storage to help you save space on your computer, but that would interfere with Sims 4, especially when you tried to save.
Point is, clear more space on C, ideally another 15 GB or so, and let me know whether OneDrive is present.