Hello I just got the same error message "Unable to find file Graphics/Titles/okladka1".
I went into the Graphics folder, Titles and the name of the image was written like this "ok³adka1", I removed the "3" and add "l" and then it let me open the game.
Not sure why that happened, but after I read someone else had the same problem I thought maybe this could help anyone else with the same issue.