Always return Error FBErrorCategoryUserCancelled while login with facebook in my application

Question

In my Application there are three ways of login. one of them is login with facebook. But when I click on facebook button it ask me for accesing permissions, when click OK<

Answer 1

In my case it was because the facebook app's sandbox mode was still on, and therefore result in FBErrorCategoryUserCancelled for anyone who is not an administrator/developer/tester of the app.

To turn off sandbox mode on facebook, go to https://developers.facebook.com/apps/YOUR_FACEBOOK_APP_ID/review-status/

See where it says "Do you want to make this app and all its live features available to the general public?", make it to be YES. (You might need to insert a contact email before you can access this option).

Or, if you don't want to make the app go public just yet, invite the tester to be an admin/developer/tester of the app. The person need to accept your invitation before he can use it.