Students are either enrolled through the University of Montana (Mountain Campus) or the Missoula College (909 South Avenue).  If you receive a "College Restriction" error message when you are registering, it means the course you are trying to add is offered by the opposite college from the one in which you're enrolled.  As a Mountain Campus student, you would need to fill out a College Restriction Override form to add the course.  You can add up to 6 credits of Missoula College coursework per semester.