CoursePress Pro Reports not generating individual lesson reports

When I go to the Reports page on Coursepress Pro and select a student (or multiple students) and select a particular lesson from the bottom dropdown, no report is generated. A window comes up and replaces my current window. It has a header, but no information. If I choose a single student, or multiple students and "All Units" , a pdf is generated properly and a separate window comes up asking if I would like to read or save the generated pdf. That works fine.