This isn't the desired answer, but as long as you have access to the course, you can go to Courses, view All Courses, and then get to it from there (select it rather than trying to make it a favorite). If your institution has blocked access for instructors until a certain date, that won't help.
@rebfoste , I suspect that you cannot yet "favorite" the Spring 2017 courses because they haven't yet been published. Please refer to How do I customize my Courses list? This is the relevant part of the guide:
If a course is unpublished, and students are allowed to view unpublished courses before the course start date, students cannot favorite the course . Students can hover over a star icon for an unpublished or concluded course and view a message indicating that the course cannot be added as a favorite. However, instructors can favorite unpublished courses .
...oh, and sorry, @rebfoste , I assumed because of the message you're getting that you are a student. Most schools do not allow students to work on courses in upcoming semesters until the first day of classes, or close to that--but you did say you need to work on the courses, so perhaps you're a teacher? If you are a teacher but cannot access the courses by clicking on them as @James recommended, you might have been added to the courses in the wrong role, in which case you will need to contact your school's admins to get that straightened out.
Along with what stefaniesanders said, it's possible that your school admin has set an availability date for the Spring term that is in the future. The resolution is the same though - contacting your school admins.