My only save brings up a frozen screen and shuts down everything, so beware of this happenng to you. I have not been playing that long and just entered some doors I needed the scribe for. I was on top of some structure on the side of the next set of doors. I had just killed the creature with arrows there.
My reasoning is that this will happen if you are not on solid ground, or if there is too much going on on screen (many were fighting on the other side), or , since you can continue playing while it is saving, you should not even move at that time. In other words, only save when nothing else is going on and you are on the ground, and don't do what I did and turn off auto save, turn it for every 5 minutes.