Try each of the following steps in order until the issue is resolved:
  1. Enter values for all Translation Tables
     
  2. Edit Translation Table to assign the appropriate Numeric Equivalent and Cut Off value for each letter grade.
     
  3. Recreate the report parameters
     
  4. In the Grade Report on the Marking Columns tab, highlight the selected marking column on the left. Edit the Grade (Low) and Grade (High).