The game allows to restore up to the past 3 turns, by using the Load Menu windows. But it may happen that a severe crash leads to this Load Menu Windows not functioning. This is caused by Windows UAC or the anti-virus, that is blocking the file from being edited/written.
Here is the procedure to restore manually a game.
First, check where the game saves your games (see the white line of text at the bottom of the options panel) [ATTACH]24978[/ATTACH]
Hofstadter's Law: "It always takes longer than you expect, even when you take into account Hofstadter's law."