@smooshnoosh It sounds like OneDrive might be the issue here: the error you got means it's having trouble syncing, which could also mean Sims 4 isn't able to write to a synced folder like the user folder in Documents. Anyway, try pausing OneDrive's syncing:
Once you do that, it's a good idea to disable its syncing of Documents entirely, since that's likely what caused the problem in the first place.
@smooshnoosh Yes, it's easy enough. Scroll down a bit here:
Be sure to grab any files you might want from OneDrive first: for example, it might hold Sims 4 content or other important documents. When you unlink or stop syncing, and maybe also when you uninstall OneDrive, sometimes your files will end up only in OneDrive and not on your hard drive. You could drop the files you want to keep into any folder that isn't currently being synced (e.g. Downloads) before uninstalling OneDrive, then restore them afterwards.
