I also just had this issue happen, tried opening the craft a cure menu in the apothecary table and then the game completely froze after turning the brightness of the game turned down as it would when you open a separate menu except the menu didn't open. Playing on Windows PC and I have mods but wasn't using them when the freeze happened. No buttons re-start the game and the game doesn't crash on its own or seem to know that there is an issue (no spinning loading wheel or anything). Has only happened once so far. For me though, the sim wasn't actively working the career (not seeing clients at home or working from home). Just before trying to craft a cure I had used the table to purchase apothecary ingredients and I was quickly menu-ing while using 3X speed.
What do you mean by you weren't' using the mods when it happened ? Did you test this on a empty mods folder?
