View [auth.login] not found

I am working on login part of application where i am creating two seperate login for admin and user. My Controller structure is like :

 Controller -    Admin (For Admin)
       LoginController.php
       ....   Auth  (For Normal user)
       LoginController.php
       ...

Views:

 Admin 
   login.blade.php
 auth 
   login.blade.php

till now i'm working on the admin part.

LoginController.php

<?php

namespace App\Http\Controllers\Admin;

use Auth;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\AuthenticatesUsers;

class LoginController extends Controller
{
    use AuthenticatesUsers;

    /**
     * Where to redirect admins after login.
     *
     * @var string
     */
    protected $redirectTo = '/admin';

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest:admin')->except('logout');
    }

    /**
     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
     */
    public function showLoginForm()
    {
        return view('admin.auth.login');
    }

    public function dashboard()
    {
        $this->validate($request, [
            'email'   => 'required|email',
            'password' => 'required|min:6'
        ]);
        if (Auth::guard('admin')->attempt([
            'email' => $request->email,
            'password' => $request->password
        ], $request->get('remember'))) {
            return redirect()->intended(route('admin.dashboard'));
        }
        return back()->withInput($request->only('email', 'remember'));
    }

    /**
     * @param Request $request
     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
     */
    /*public function logout(Request $request)
    {
        Auth::guard('admin')->logout();
        $request->session()->invalidate();
        return redirect()->route('admin.login');
    } */
}

RedirectIfAuthenticated.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Support\Facades\Auth;

class RedirectIfAuthenticated
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @param  string|null  $guard
     * @return mixed
     */
    public function handle($request, Closure $next, $guard = null)
    {
        switch($guard){
            case 'admin':
                if (Auth::guard($guard)->check()) {
                    return redirect('/admin');
                }
                break;
            default:
                if (Auth::guard($guard)->check()) {
                    return redirect('/');
                }
                break;
        }
        return $next($request);
    }
}

web.php

Route::group(['prefix'  =>  'admin'], function () {

    Route::get('login', 'Admin\LoginController@showLoginForm')->name('admin.login');
    Route::post('login', 'Admin\LoginController@login')->name('admin.login.post');
    Route::get('logout', 'Admin\LoginController@logout')->name('admin.logout');

    //Route::get('dashboard', 'Admin\LoginController@dashboard')->name('admin.dashboard');

    Route::group(['middleware' => ['auth:admin']], function () {

        Route::get('/dashboard', function () {
            return view('admin.dashboard.index');
        })->name('admin.dashboard');

    });

whenever i access dashboard throgh url i get View[auth.login] not found.

via Chebli Mohamed