I have web app running in Google App Engine/Java. The app allows user to login using their facebook account.
The implementation works perfectly but sometimes an error happened and said no email in API response.
Email is already included in scope: scope = "email,user_birthday,user_location";
I explicitly required email:
"https://graph.facebook.com/me?access_token=" + accessToken + "&fields=email,id,name,birthday,gender";
But still API sometimes don't have email returned. How to reproduce the error with my facebook account?
When will the response don't include email? Is email not required in all facebook registraion? Any workaround for this?