Now this is strange.
I just downloaded the new version 86.3 to replace my old version 86.0. I'd just been playing 86.0 today, in fact, when I decided to check if I'd missed a new version. Anyway, on a hunch, I didn't delete my old version until after downloading, extracting and running the new version, in case something didn't work.
And work something did not. For some bizarre reason, I can load the game I'd saved in slot 1, the game I'd saved in slot 2, but NOT the game I'd saved in slot 3; it's simply not appearing. 3 is my most current save, although I'd also made 2 today as well. But I can load save 2, but not 3. Oddly specific. Also, for the sake of experimentation, I loaded my slot 2 game, and found that for some reason my bot had been stripped down to her underwear, and her right arm (and ONLY her right arm, even thought it was almost identical to her left arm) was missing.
What's with that?
EDIT: Never mind, I was able to fix the problem by manually copy-pasting the saves folder from the old version's _data folder into the new one's, rather than relying on the system saves. But that's still something that should probably be looked at. Thank god I didn't do my usual thing of deleting the old version of a game to save space while downloading the updated one!