Good news and bad news.
Good news, rather - great news - Mina and Flynn gave birth to a baby imaginary friend on their first shot. I was having a blast having him grow up. It was his young adult birthday, I went to send him to the dresser when suddenly the game crashed. I was sad, but figured I had saved a sim-day prior (almost certain of it, actually) but when I went back it was Wednesday in game (which I wanted it to be, as it was his young adult birthday) but rather... it was the Wednesday of his prior teen birthday. I lost all of my skill gain (level 6 in nectar making and level 7 in Street Art) and all of the work done towards his goals (which was a LOT).
I'm really discouraged, but not enough to stop playing... just enough for tonight, and possibly tomorrow.
I'm so bummed, but it's my last Sim.