Well, I should update what I wrote earlier. I'd recommend waiting to graduate any of your sims right now. The first sim I mentioned? Her diploma has shown up in the inventory of every household I rotated to after her graduation. Yet she didn't get her diploma, all she got was her graduation portrait. There's no other weirdness, it's just annoying seeing them in the other household's inventories. I don't know if it's a game breaking bug YET, I have no issues loading the save. I reported it at AHQ and wanted to let you all know since you're rotational players too.
