If there are other users (such as Grandparents) on the profile update form, their first and last names must be added in order for the form to submit without error.

Also specific to Grandparents, the Grandparent Relationship Type must be enabled.

This error message can also happen if one parent is auto-populating their household information and a spouses household information. In this case the user should
  1. Remove the Mother, Father and Student from the Form.
  2. Save the Form
  3. Add the student back as a User Regarding.
  4. Re-enter the information for both the mother and father.
  1. Uncheck any instance of the 'Address Same as Student' box, and manually enter the address (this is another form of auto-populating)