I'd reckon you read through this post https://itch.io/post/3246092, but in case you didn't, go to AppData\Local\AtC_BB\Saved\SaveGames and move the .sav file out of there, put it somewhere like your desktop, then start a newgame to create a new save game, quit, replace the new .sav file with your old one and it should function properly now. To find your appdata folder, type %appdata% in your search bar and it should pop up.