"War by the rules"

Please advise what to do.
We can't load a previously saved game.
First, it said that my opponent (Mopdas) is not mentioned in the game, and after I sent him the map and saves, it started saying that the sum doesn't match, error code 0.2.0... see the screenshot.
As an external factor, I'll say that Mopdas recently reinstalled Windows, and during that time, I managed to play with another opponent (I took the saves out of the folder for the duration of the game, and now I've put them back in).