appointement letter blocked help tourist visa

[nourhan003 0]

hello, my husband filed form ds160 for my father to came to us to visite me he received confirmation letter by email but my father opened the systhem from morroco and choose the date of appointement but when the page appear is written print this page after that the page expired

plz how can my father get new appointement letter ?? should he return to ds 160 or should he delete ds 160 and prepare new one with new interview ?? because when he want to apply for another interview the systhem need the id number and it s written in the appointement that was expired page ??

i need ansewer as soon as possible because we want realy that he came to visite me as soon a possible

thanks