Try each of the following steps in order until the issue is resolved:
  1. Customize the Gradebook to show all assignments:
    1. Open the Gradebook for that class
    2. Select Customize
    3. Select All Assignments

In version 7.83

                   a.  Select to view the gradebook grid

                   b.  Select to Show: all assignments from the drop-down menu
  1. In Gradebook, view the grades for a teacher's class, the average, grade, and posted grade columns automatically appear
  2. Select to view each marking column, starting from the beginning
  3. Ensure the administrator allows teachers to view all marking columns
  4. Verify that the teacher has the preference Display Warning Message Before Session Timeout enabled.