Unable to Submit on Firefox

I have a form here: http://www.apnaastrologer.com/horoscope/

It works on Chrome, but not on Firefox. The wpcf7-response-output gets populated with “Validation errors occurred. Please confirm the fields and submit it again.”, but the class wpcf7-display-none remains attached to it, and thus it stays hidden. Also, I don’t know why validation errors occur even when all fields are being filled.

https://wordpress.org/plugins/contact-form-7/