Sorry, I messed up something and actually to fix a bug I had to change the saved game format.
Hopefully the new version will work better, but you're going to lose your saved games with it, sorry... :-(
I know this is very annoying and I tried my best to avoid such issue, but sometimes the root of a bug is inside the structure used for the saved games and it's inevitable to lose them.
I direly hope it'll be the last bug of this kind.