Hey, I would love to help, but that's quite hard since the error is in Russian. Does this error also appear when you try to open Notepad2.exe yourself? If not, try open it yourself, and it should still work. If that doesn't work, try this version. If that doesn't work, try moving the .notepad folder to something like Desktop. Perhaps Notepad2 can't handle the Russian characters. If that doesn't work I'm not sure what else there is to try. Sorry.
If you use the alternative version, you will have to save the file when you open it, to let the game know you opened that file.