Fragment transaction can't addToBackstack in Marshmallow

Add this piece of code to the underlying Activity

@Override
public void onBackPressed() {
    if (getFragmentManager().getBackStackEntryCount() > 0 ){
        getFragmentManager().popBackStack();
    } else {
        super.onBackPressed();
    }
}

Reference:

http://stackoverflow.com/a/28322881