1. Log into Faculty Access for the Web as the teacher of the affected class
  2. Review the category average columns to locate any category that has a letter grade value entered for students.
  3. Delete the letter grade(s) and click Save
  4. To recalculate the category average, take the following steps:
    1. Select Gradebook Edit Categories
    2. Change the number to drop for the affected category to a new value and save
    3. Change the number to drop back to the original value and save
The error should no longer occur for the NetClassroom users.