We have upgraded Gravityform version 2.7.7 from 2.4.
Submit button was working in 2.4 version but after upgrading to 2.7.7 is not working.
Please find below form URL. https://msgreyandwhite.celgenevalwp.com/
Form is in home page " Register for More Information"
The submit button is not the default button included with Gravity Forms, a custom button has been added in an HTML field and then the footer containing the default button hidden. The form scripts require the default button to be visible for the form to submit.
I recommend removing the HTML field containing the custom button and then on the Form Settings page of the form disable legacy markup.
You’ll then be able to change the position of the default submit button by editing the button settings in the form editor.