angularjs - Firebase logout permission error -

when trying logout out of firebase unauth() error saying

error: permission_denied: client doesn't have permission access desired data.

this controller:

 .controller('statuscontroller', [ '$scope', '$state', '$rootscope', '$firebase', '$firebaseobject', 'firebase_url', 'authentication', function($scope , $state, $rootscope, $firebase, $firebaseobject, firebase_url, authentication) {       var ref = new firebase(firebase_url);         $scope.logout = function(){            $state.go('login');            authentication.logout();       };   }])   .factory('authentication' , ['$firebase' , 'firebase_url', '$q' , function( $firebase , firebase_url, $q, $scope){      // other code above here     var ref = new firebase(firebase_url);      logout: function(){         // $scope.destroy();             window.localstorage.removeitem("firebase:session::outfitpictest");              return ref.unauth();          } //logout      } // object       return myobject;   }]);