Indeed! Thanks a lot for spotting this. I built a new shop mechanic, that automatically will adjust the amount of items you buy if you try to buy more than you can carry. (example: you have 95 potions, can carry 99 and want to buy 10. Now the game automatically reduces the selected amount to 4 potions to buy)
This meant that I had to change which script is called for every single shop. To make sure I don't miss any, I marked the old (no more functioning) script with "[Old Script]". But it seems like I missed the smithy 😅
I'll try to get a fix ready in a few minutes. So if you play the rom you should be able to continue with your save file and buy that knife 😊