This was an error I ran into as well, in new save files, some before the latest set of updates and some after. It was across multiple circumstances but they all seemed to occur when a person's fat/stuffing level changed, such as:
-resurrecting somebody with a thick meat
-getting fed by Isabella
-digesting in combat
It occurs commonly but not necessarily consistently (as in, I can try to duplicate the error by reloading and trying the exact same triggering mechanism, but the game will often function okay the second time.) Attached is a sample error screen. 