I think I've tracked the origins of a very annoying bug, when suddenly your save button in a main menu becomes greyed out and some time after you start getting a mid-dialogue save message and are unable to save the game. It actually is tied to NPCs reacting to summoned creatures like familiars etc. Whenever you walk near NPCs with a, lets say, summoned spider, they tend to comment on it and in some special occasions it can break the game, so hear me out on this specific situation:
If you summon a familiar (i went with a spider) and walk near the closed (!) ogre+bugbear barn, the ogre will comment on a familiar through the closed door and start running towards it , which immediately results into the greyed out save button in the menu, HOWEVER you can still use quicksaves. Yet. But when you kill the summon afterwards, save again, then reload and THEN try to save, you will consistently get the mid-dialogue message and inability to save your games. I think it is somehow related to the game counting this "comment" on your familiar as a conversation and after you kill it, the conversation becomes "eternal". So for those encountering this issue I suggest to stop using familiars/animal companions for the time being.
I filed a report to the devs but this was before I tracked the initial bug trigger. I will file another one tomorrow. Hope this helps someone to progress their games without losing tons of hours of gameplay at once.
