Laravel：ルート[ログイン]が定義されていません

Laravelaでアプリケーションを作成していますが、たとえばhttp://example.comのURLにアクセスしようとすると、この奇妙なエラーが返されますか？これは、/ loginにアクセスしていない場合にのみ発生しますか？

InvalidArgumentException in UrlGenerator.php line 304:
Route [login] not defined.

コード：

use App\Http\Controllers\Frontend;

Route::group(['domain' => 'localhost', 'namespace' => 'Frontend'], function() {

    Route::group(['middleware' => 'guest', 'namespace' => 'Guest'], function() {
        Route::get('/', function() { return Redirect::to('/login'); });
        Route::get('/login', 'LoginController@getView');
        Route::post('/login', 'LoginController@onPost');
    });

    Route::group(['middleware' => 'auth', 'namespace' => 'User'], function() {
        Route::get('/', function() { return Redirect::to('/home'); });
        Route::get('/home', 'HomeController@getView');
        Route::get('/logout', 'LogoutController@performLogout');
    });
});

Route::group(['domain' => 'admin.localhost'], function() {
    Route::get('/', function() {
        return 'Housekeeping will be making an appearance soon!';
    });
});

これが私のLoginControllerです：

<?php
namespace App\Http\Controllers\Frontend\Guest;

use Auth;
use App\User;
use App\Http\Controllers\Controller;
use Validator;
use Redirect;
use Illuminate\Http\Request;
use App\Database\Frontend\User\Player;
use App\Database\Frontend\WebsiteLogin;

class LoginController extends Controller
{
    public function getView()
    {
        return view('frontend.login');
    }

    public function onPost(Request $request) 
    {
        $validator = Validator::make($request->all(), [
            'mail'     => 'required|email|exists:users',
            'password'  => 'required'
        ]);

        if ( $validator->fails()) {
            return Redirect::to('/login')->withErrors($validator->messages());
        }
        else {
            if (!Auth::attempt(['mail' => $request->input('mail'), 'password' => $request->input('password')])) {
                $this->addNewWebsiteLogin($request, Player::where('mail', $request->input('mail'))->pluck('id')->first(), "0");
                return Redirect::to('/login')->withMessage('Email and password do not match')->withColor('danger');
            }
            else {
                $this->addNewWebsiteLogin($request, Auth::user()->id, "1");

                $user = Auth::user();
                $user->last_online = time();
                $user->save();

                /*if (config('frontend.government_only') && (Auth::Guest() || Auth::user()->roleplay->government_id == 0)) {
                    Auth::logout();
                    return Redirect::to('/login')->withMessage(config('frontend.site_name') . ' is only open to government individuals at this moment, too bad.')->withColor('danger');
                }*/

                return Redirect::to('/home')->withMessage('Welcome back!');
            }
        }
    }

    private function addNewWebsiteLogin(Request $request, $userId, $status) {
        $websiteLogin                    = new WebsiteLogin;
        $websiteLogin->user_id           = $userId;
        $websiteLogin->request_ip        = $request->ip();
        $websiteLogin->request_system    = 'TODO';
        $websiteLogin->request_browser   = 'TODO';
        $websiteLogin->login_status      = $status;
        $websiteLogin->save();
    }
}