Yes, I have learned to always repair the game after an update. Yes, Onedrive is on and has always been so without any kind of problem. I'm rather vexed at this whole turn of affairs. And yes, I do have a backup. In fact, several. After my last saves folder got corrupted, I have taken the advice to do a weekly backup, just to be on the safe side. --- Besides the pre-Patch backup.
Thank you for pointing me toward the tech forum. I shall see if I can follow the instructions adequately to not totally mess up my gaming unit. And I shall pray it does the trick. Thank you so very much!