Hello!
I'm sorry that that happened, maybe you can try to put this save after fighting the pet inside of the saved folder. To do that, press Windows + R and open this folder: %localappdata%\Kalyskah_RPG\Saved\SaveGames
Then add the save I linked there. Try to load the game on this save and see if the error persists. If it persists, it might be related to your PC maybe nor having the minimal requirements to load that level =(