Inserting Engage in a Powerpoint Presentation not working

I cannot insert an a new Engage Interaction in a Powerpoint presentation. Three of the presentation's four slides contain either an Engage Interaction or a game.  I open the presentation, highlight the blank (fourth) slide, click the Articulate tab, click the Engage Interaction icon, and the Quizzes and Interactions dialog box appears.  Regardless of selecting Create New or Add Existing, I am limited to working with quizzes.