When you get an error ” student already exists” yet that student is not admitted to the school then you should check on the admission number if it is available. This mostly happens when the admission number is already taken and is used by another student in the school. Check on ‘edit student details’ to confirm that the admission is free. Also, check under “Admissions => Inactive students” and confirm if that admission is taken by any of the inactive students.
Check the video below to see how to edit the students.