No bid for this instrument?

Around 10:30 AM (NY time) I tried to short Gold (the December 2024 contract, currently the most liquid Gold contract) but Webtrader refused the trade and gave me this error message : "
No bid for this instrument. Order not accepted.
This instrument does not have any bid right now. You can place the order as the “LIMIT @ " or cancel it.”

A few moments later the price of gold dropped like a pile of bricks, without me.

How is that even possible?