Laravel 5.2.45 Login/Register (Auth) Problem

Hi,

I have now wasted a lot of my time to find out, but without any luck. I was developing my admin with Laravel 5.1 and upgraded to L5.2 by running command : composer update (ofcourse composer.json file edited ) php artisan --version => Laravel Framework version 5.2.45

now my login/register/reset (all auth methods) not working, it shows only the view, after submit the form, i get HTTP 500 internel Error

and there is nothing in log file. and log file is writable, because when i mistype any command in artisan, its added to the log.

AuthController.php

namespace App\Http\Controllers\Auth;

use App\Models\User;
use App\Models\Role;
use Validator;
use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\ThrottlesLogins;
use Illuminate\Foundation\Auth\AuthenticatesAndRegistersUsers;

class AuthController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Registration & Login Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles the registration of new users, as well as the
    | authentication of existing users. By default, this controller uses
    | a simple trait to add these behaviors. Why don't you explore it?
    |
    */

    use AuthenticatesAndRegistersUsers, ThrottlesLogins;
    
//    private $redirectTo = '/';
//    private $maxLoginAttempts = 10;

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

    /**
     * Get a validator for an incoming registration request.
     *
     * @param  array  $data
     * @return \Illuminate\Contracts\Validation\Validator
     */
    protected function validator(array $data)
    {
        return Validator::make($data, [
            'name' => 'required|max:255',
            'email' => 'required|email|max:255|unique:users',
            'password' => 'required|confirmed|min:6',
        ]);
    }

    /**
     * Create a new user instance after a valid registration.
     *
     * @param  array  $data
     * @return User
     */
    protected function create(array $data)
    {
        return User::create([
            'role_id' => '3',
            'name' => $data['name'],
            'email' => $data['email'],
            'password' => bcrypt($data['password']),
        ]);
    }
}```
´´´

routes.php
```<?php

/*
|--------------------------------------------------------------------------
| Application Routes
|--------------------------------------------------------------------------
|
| Here is where you can register all of the routes for an application.
| It's a breeze. Simply tell Laravel the URIs it should respond to
| and give it the controller to call when that URI is requested.
|
*/

Route::get('/', function () {
    return view('home');
});

//Admin
Route::group([
        'middleware' => ['auth', 'roles'], 
        'roles'      => ['administrator', 'manager'],
        'prefix'     => 'admin',
        'namespace'  => 'Admin'], function () {
    
        Route::get('/', function (){
            return redirect('admin/dashboard/');
        });        
        Route::get('dashboard', 'DashboardController@index');
        
        //Translation
        Route::resource('translation', 'TranslationController', ['only' => ['store', 'destroy']]);
        
        //Words            
        Route::resource('word', 'WordController');
                       
        //Users            
        Route::resource('user', 'UserController');
                
        //Ajax
        Route::get('get-user-ajax/',   'UserController@getUsersAjax');
        Route::get('get-word-ajax/',   'WordController@getWordsAjax');
        Route::get('words-autocomplete/',   'TranslationController@getAutoCompleteWordsAjax');
        Route::get('delete-sound/{sound?}',   'WordController@deleteSound');
        //Route::get('remove-translation/',   'TranslationController@removeAjax');
        
        //grammar
        Route::resource('grammartype', 'GrammartypeController');
        Route::resource('grammarproperty', 'GrammarpropertyController');
});


Route::Auth();