This Query will arise due to a discrepancy with the information in your School Details table.
Click on your school name at the top right of ScholarPack, above the student search bar, or go to Admin > Config > Core Setup > School.
You will need to check the Highest and Lowest Year group recorded agrees with the School Type you have recorded. Click on Edit to view the school type details (as opposed to the number).
You will need to select a School Type which matches year groups up to your highest year in the example above.