This is usually caused by the course being a full year or a 2nd Term course and the change is being made in the 2nd Term or any term other than the first. In order to add a section, you will need to toggle back to the 1stTerm.

To do this, navigate to:
  1. Academics
  2. Scheduling > Requests and Schedules
  3. Classes and filter for the School Level and 1st Term 
  4. Expand the Department the course is in
  5. Click Manage Sections to create sections for the course
  6. Click + Add Section
  7. Complete the required fields