How to interpretate Amoris Laetitia?

What are the "Dubia"? Why are there so many divergences on the interpretation of Pope Francis' exhortation "Amoris Laetitia"? In his famous EWTN's TV show, Raymond Arroyo will look for answers with Fr. Gerald Murray (Diocese of New York), PhD in Canon Law by the Gregorian University of Rome, and Robert Royal, PhD in Compared Literature by the Catholic University of America, a university professor and author of several books.