O.K. This is strange:
I loaded one of the old saved games in my wife's profile. Then I saved it again with a new name. Saving and loading seems to work ok in this profile, even if I quit the game, start it again and load a saved game.
My own profile doesn't work at all.
So I deleted it and created a new profile with a different name. Then I created new characters and started from scratch. Now saving and loading seems to work. I can quit the game and can load any saved game when I restart it. Just as it is supposed to be.
I don't know what changed, besides I hadn't deleted the old profile before. I lost my saves, but at least I can play now, hopefully without any further complication.
Greetings
