So I have heard about this weighing machine bug that has been occurring. The weighing machine will bug out and display money instead of actual scale, and when a stamp is placed, the scale will display ERROR. I have managed to track it down, and it seems like leaving a package overnight on the scale will bug it. I have tried it with another save file, and it still worked. Let me know if it works for you.
I have a video recording ready if you wish.