I completed all prerequisite course for NAR108 - Advanced Chemistry: Cooking up the Perfect Batch. But I am not able to click start button for this course. The butteon is in light green which not allow me to click.

Hey Aurpex, 

Apologies for the lack of response on this issue, is it still occuring?

No，the button became clickable  a day after I posted this thread.

Perfect thank you, if it reoccurs don't hesitate to report it again.