Did you create an account for each of the family members in the beginning and then try to add one as another's family member to scchedule an appointment for them together? If so, you have to remove all the relevant information from the family member's (whom you are adding) account. I think this is a design bug of the visa application system.
【在 o**********a 的大作中提到】 : I got this error message when i trying to fill out online application. : And now I cannot do anything. : Any suggestion?