Remove one of the enrollments for that year.
  1. Open each record and check the Enrollments tab
  2. Identify which year is duplicated.
  3. Delete the enrollment from one record
OR
  1. Open the Applicant record
  2. On the Applications Tab
  3. Make sure there are years listed in the Year Apply field for all applications
    If enrolling a new applications for a returning student, this error can occur when we do not have the year apply defined for all applications