Note: As of July 9, 2018, Blackbaud's School Management solutions (which include Core, onBoard, onCampus, onMessage, and onRecord) are utilizing a new top level navigation. This primarily affects users performing administrative tasks-constituent navigation for most parents, students, faculty, and alumni will remain the same.  
We appreciate your patience as we work to update our documentation. If you are seeing this message, the content of this solution is still being vetted for possible updates. Please refer to this mapping document if you need assistance finding a task in the new navigation.

Once a Candidate is inactivated for a given entering year additional entering years need to be Added in Core > School > Years & Terms > Add in order to re-activate the candidate for the same year.