Send form to different email

Hi, I follow this guide in order to send the form based on user selection dropdown to different emails:

https://conditional-fields-cf7.bdwm.be/docs/faq/can-i-send-the-form-to-different-email-addresses-based-on-the-selection/

Is working but in the CF7 settings I always have this validation error:

See the screenshot:

https://tinyurl.com/yb8zx8w9

There is a way to fix it?