Email signup form not working

I am having trouble subscribing to the Wizard Of Oz virtual fan celebration, using my email, when I subscribe it says enter a value, what does this mean?

This is a duplicate ticket to https://www.jotform.com/answers/2606984 which is already addressed. So, we are marking this ticket as answered. If you have any questions with this issue, we request you to follow-up on the other ticket.

Thank you!