If the button for "Create a Syllabus" is greyed out and not clickable, it is because a syllabus has already been created for this class:




You can edit the syllabus using the "Edit Your Syllabus" button. However, you can also delete the syllabus using the "Delete a Syllabus" button. Doing this will enable the "Create a Syllabus" button to start a new syllabus.