The reason this is happening, for example, is if you have the  Academic Performance Category Description listed as Honor Roll and then within Honor Roll you have subcategories as  Q1, Q2 , Q3, Q4. When you try to run the Honor Roll for Q2, it will give you the error referenced above. This is because the subcategory with the lowest priority has the highest standards, so any student that falls into the subcategory with the lowest priority will no longer be eligible for subcategories with higher priorities. 

If you have a Category Description listed as Honor Roll and then Honor Roll was broken out into 3 levels: High Honors, Honor Roll, and Honorable mention, then there would be 3 subcategories within the Category Description of Honor Roll. This is the correct way to set up Academic Performance because if  User makes High Honors, they would no longer be eligible for Honor Role or Honorable mention, if a User makes Honor Role, they would no longer be eligible for Honorable mention. This is the way Academic Performance is set to run.

For more information on setting this up, see Academic Performance.