Ah, okay, I know why. It’s because that version is prepared for Steam, and I forgot that it doesn’t work if you try to open it elsewhere. I apologize — I’m going to update the game right now, and I assure you that you’ll be able to open it without any problems. I’m truly sorry.
I’ve updated the game. Please download it again, and I guarantee that this time you won’t have any issues. Once again, I apologize for the inconvenience.