Coursepress Pro Error when viewing course

When trying to view a new course we are getting this error: Warning: array_key_exists(): The first argument should be either a string or an integer in /home/martiel/public_html/theartcademy.com/wp-content/plugins/coursepress/includes/classes/class.course.php on line 374

Also, none of the course elements are displaying when viewed. I have enabled the Support Dashboard.