I faced the same problem, additionally following happened: At that point - I finished the spell of making - unfortunately at the same time the research in one field was finished and the screen "what to research as next" popped up. It was not possible to exit that screen und to leave the game . I had to push the buttons Strg-Alt-Entf to exit the game. The achievement for winning the game was not reached. I must say i did not play the campaign, I played a random generated game.
