diff --git a/modules/core/server/controllers/errors.server.controller.js b/modules/core/server/controllers/errors.server.controller.js
index db81a8ec86..935a9299d4 100644
--- a/modules/core/server/controllers/errors.server.controller.js
+++ b/modules/core/server/controllers/errors.server.controller.js
@@ -8,10 +8,10 @@ var getUniqueErrorMessage = function(err) {
 
 	try {
 		var fieldName = err.err.substring(err.err.lastIndexOf('.$') + 2, err.err.lastIndexOf('_1'));
-		output = fieldName.charAt(0).toUpperCase() + fieldName.slice(1) + ' already exist';
+		output = fieldName.charAt(0).toUpperCase() + fieldName.slice(1) + ' already exists';
 
 	} catch(ex) {
-		output = 'Unique field already exist';
+		output = 'Unique field already exists';
 	}
 
 	return output;
diff --git a/modules/users/client/config/users.client.routes.js b/modules/users/client/config/users.client.routes.js
index 9b0546360e..4c00bc0651 100644
--- a/modules/users/client/config/users.client.routes.js
+++ b/modules/users/client/config/users.client.routes.js
@@ -36,7 +36,7 @@ angular.module('users').config(['$stateProvider',
 				templateUrl: 'modules/users/views/authentication/signup.client.view.html'
 			}).
 			state('authentication.signin', {
-				url: '/signin',
+				url: '/signin?err',
 				templateUrl: 'modules/users/views/authentication/signin.client.view.html'
 			}).
 			state('password', {
diff --git a/modules/users/client/controllers/authentication.client.controller.js b/modules/users/client/controllers/authentication.client.controller.js
index a1b349f4f1..fed9225718 100644
--- a/modules/users/client/controllers/authentication.client.controller.js
+++ b/modules/users/client/controllers/authentication.client.controller.js
@@ -4,6 +4,9 @@ angular.module('users').controller('AuthenticationController', ['$scope', '$http
 	function($scope, $http, $location, Authentication) {
 		$scope.authentication = Authentication;
 
+		// Get an eventual error defined in the URL query string:
+		$scope.error = $location.search().err;
+
 		// If user is signed in then redirect back home
 		if ($scope.authentication.user) $location.path('/');
 
diff --git a/modules/users/client/views/authentication/signin.client.view.html b/modules/users/client/views/authentication/signin.client.view.html
index 5345a5dc6c..0d78a1391f 100644
--- a/modules/users/client/views/authentication/signin.client.view.html
+++ b/modules/users/client/views/authentication/signin.client.view.html
@@ -18,12 +18,12 @@ <h3 class="col-md-12 text-center">Or with your account</h3>
 					&nbsp; or&nbsp;
 					<a data-ui-sref="authentication.signup">Sign up</a>
 				</div>
-				<div class="forgot-password">
+				<div class="text-center forgot-password">
 					<a data-ui-sref="password.forgot">Forgot your password?</a>
 				</div>
-				<div data-ng-show="error" class="text-center text-danger">
-					<strong data-ng-bind="error"></strong>
-				</div>
+				<alert type="danger" data-ng-show="error" class="text-center text-danger">
+					<span data-ng-bind="error"></span>
+				</alert>
 			</fieldset>
 		</form>
 	</div>
diff --git a/modules/users/server/controllers/users/users.authentication.server.controller.js b/modules/users/server/controllers/users/users.authentication.server.controller.js
index d2c5acd27c..ea4c9e5e14 100644
--- a/modules/users/server/controllers/users/users.authentication.server.controller.js
+++ b/modules/users/server/controllers/users/users.authentication.server.controller.js
@@ -83,12 +83,15 @@ exports.signout = function (req, res) {
 exports.oauthCallback = function (strategy) {
 	return function (req, res, next) {
 		passport.authenticate(strategy, function (err, user, redirectURL) {
-			if (err || !user) {
-				return res.redirect('/#!/signin');
+			if (err) {
+				return res.redirect('/authentication/signin?err=' + encodeURIComponent(errorHandler.getErrorMessage(err)));
+			}
+			if (!user) {
+				return res.redirect('/authentication/signin');
 			}
 			req.login(user, function (err) {
 				if (err) {
-					return res.redirect('/#!/signin');
+					return res.redirect('/authentication/signin');
 				}
 
 				return res.redirect(redirectURL || '/');
diff --git a/modules/users/server/models/user.server.model.js b/modules/users/server/models/user.server.model.js
index 3f2225e6f1..4ffd1f1738 100644
--- a/modules/users/server/models/user.server.model.js
+++ b/modules/users/server/models/user.server.model.js
@@ -52,6 +52,7 @@ var UserSchema = new Schema({
 	email: {
 		type: String,
 		trim: true,
+		unique: true,
 		default: '',
 		validate: [validateLocalStrategyEmail, 'Please fill a valid email address']
 	},