This happens when you have previously signed up for the free trial and have not yet registered the access code for the full course to your account. 

To reset the expiration date, copy the access code from the email that was sent to you (the same access code is also shown on the order history on your main dashboard), click the Online Courses tab, click the “Add Course” button on upper right portion of the page, and paste the access code on the respective field. After successfully applying the code, you will be redirected to the ABA Course registration page.  Fill in the form (most of the fields will be auto-filled) and click “Submit”.  An automated email with the instructions for the course will be sent to your registered email address.