Restricting enrollment by course disqualifier prevents users from enrolling in a course based upon their previous completion of another course in the system.
For example, if a user attended a live course in 2018, the administrator may not want to allow the learner to attend the 2019 version of the same course.
Click "EDIT."
Click "Pre-requisites."
Navigate to the 'Course Access' block
Under 'Type' select 'Enrollment Blocked'
Select a course to block in 'Course' field
Click "Save."