propelcat I'd still like to know whether you can save a sim, household, or lot once you've started a scenario (and possibly ended it). The question is whether this saving process fails in all cases, or only when you're trying to start a new save. The ability to save your progress while playing a scenario is certainly a positive, but it's not conclusive.
As for the path to your user folder, if you don't have any use for OneDrive, I would suggest getting rid of it. How to do so is covered here:
📓[GUIDE] [PC] Managing OneDrive | EA Forums - 12636625
This could be the reason you're unable to save when exiting CAS, but that's not clear, and I don't want to tell you that you need to get rid of OneDrive until you've tested everything else.