Your Order not allowing submit

I have these three steps in the checkout process:

1. Billing Information
2. Additional Information
3. Your Order

I am using the “Checkout Field Editor for WooCommerce” plugin with additional billing and additional fields. I am able to proceed through all screens, but the “Next” button is grayed out on the “Your Order” screen, so I can’t place the order. When disabling this plugin, it works fine. Am I missing a setup step?

Thank you.