So I have a student who enrolled in a course through catalogue. They then dropped the course b/c they didn't think they needed it. (it's a lab safety course, non credited). They realized that they indeed do now need the course. The professor sent them the link again and when the student tried to enroll it says "There was an error processing your enrollment". I see the student on the list of enrolled students when I check it. Is there a way to remove the student so he can re-enroll? Or what do I do?