RPGler: I encountered the same problem.
It seems like the game crushes because Vierfinger Salm has to make his move.
But his move does not seem to be classed within the code. That is at least what I read out of the error report.
But I have not found a solution yet. I will report it to the german support team of gog.
Hey someone from gog just reported to my request and sended him my save file if i get a soulution i will write you again