Whenever I attempt to use /t deposit, Towny shows an error message:
[Towny] You don't have that much

This is very annoying as I can not deposit or expand my towns on the server.
Thank you!

Stale, and whichever fork existed a year ago solved this.

PS: I meant that I don’t want to make a Town Vault, like on EarthMC.

I think Gringotts philosophy was to always store items in some physical location.

I know but is there a way to do it like EarthMC, without a town vault?

It has been asked a couple of times and specifically about town vaults. I assume you mean like a 'virtual' vault for the town where those with access can use it. A bit like how an Enderchest can be used as a 'virtual vault' for a player?

Bumping this issue a bit, I have the same "issue", I'd like to have a virtual vault rather than a physical location, it that possible?

Gringotts doesn't support fully virtual accounts, sorry!

Any progress so far?

Probably somebody will need to take it upon themselves, as I'm no longer actively supporting Gringotts :(