I must say my problems with corrupted save games have nothing to do with client rulers, so I was just asking away to hear your opinions about this.
It is indeed just my personal subjective impression that this problem of save games going suddenly corrupt, which I never had before, started to turn up after the optimized script.

I think I'm going to stay with the script however, because else the game is very, very slow on my pc.
I shall start keeping save games every year for the last ten years of my campaign, instead of every 5 years like I do now. I hope this will save any future campaigns in which this problem turns up.