According to the US Embassy announcement if they find the primary applicant as ineligible person for the diversity visa program the visa will be refused and the visa fees will not be refunded. One of the following criteria can make the primary applicant as an ineligible person.
If you have missed your appointment and wish to reschedule, e-mail at IVSanaa@state.gov.
Note that the appointment time for all interviews is 7:30 a.m. If the beneficiary does not appear with required documents and appropriate interview/issuance fees before 8:00 a.m. on that day, his/her appointment will be rescheduled for a later date. It is the applicant's responsibility to contact the consular office, either by e-mail or in writing, to reschedule the appointment.
A medical examination is required as per the immigrant visa application. You must do this examination at your own cost. You should take this instruction sheet, the accompanying medical examination forms and your passport to one of the Embassy panel physicians listed.
Don't make any arrangements such as selling your house, car or property, resigning from your job or paying for non-refundable flight tickets or other travel arrangements until you have received your immigrant visa.
Notice: the U.S. Department of State has designated the U.S. Embassy in Cairo, Egypt to handle American Citizens Services cases emanating out of Yemen, as well as process visas for Yemeni citizens.
The American visa lottery program will take place in this year 2017 as DV-2017.