I'm sorry... this was one of the known issues of Ren'Py...whenever there's something changed it will have a chance to ruin the old save files... 
I'm sorry... this was one of the known issues of Ren'Py...whenever there's something changed it will have a chance to ruin the old save files...
just means i get to rekill ther evil twin doggos for what they did to our precious boy