You must respond to the request for additional documents. Your failure to do so can result in a denial of your visa application. Whether you were legally eligible to marry is a very important part of the inquiry. It appears you have the original death certificate. It is not clear why you cannot submit a copy as requested. You can read more about family immigration at http://myattorneyusa.com/family-immigration.
Answered on Sep 21st, 2016 at 3:33 AM