I have problem with the LogginButton:
LoginButton authButton = (LoginButton) v.findViewById(R.id.authButton);
authButton.setFragment(this);
Changing your fragment to android.support.v4.app.Fragment is the only solution.
So , in my case switching to the support library was no option i have solved it this way:
Don't use setFragment , instead override the onActivityResult in your Acitvity and call the fragment onActivityResult from there.
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
_loginFragment.onActivityResult(requestCode, resultCode, data);
}