alright, the Vault seems to be fixed. It seems like I made some kind of edit to the script that I forgot about.
But now I have some more issues:
when you pick an empty Deposit Box in the vault and choose to put an empty space in it, an error comes up. What I mean is:

If I picked that "Empty" space in the Deposit Box section, and select the empty space in my inventory ("Nothing") I get this error

I know there's no reason that someone would want to put an empty space in their deposit box, but accidents happen. Someone might experiment and end up crashing their game. Also, who wants errors in their games?
Issue #2: Is there a way to get rid of the "Buy More Boxes" option at the bottom of the vault. In my game, the player starts out with the max number of available slots, so there is no need to buy more.
Issue #3: I can't get the shops to work. This is what I have in the shop event

Is there something I'm missing?