Lỗi 1:

RuntimeException in EncryptionServiceProvider.php line 29:						
No supported encrypter found. The cipher and / or key length are invalid						
in EncryptionServiceProvider.php line 29						
at EncryptionServiceProvider->Illuminate\Encryption\{closure}(object(Application), array()) in Container.php line 733						
at Container->build(object(Closure), array()) in Container.php line 626						
at Container->make('encrypter', array()) in Application.php line 674						
at Application->make('Illuminate\Contracts\Encryption\Encrypter') in Container.php line 837						
at Container->resolveClass(object(ReflectionParameter)) in Container.php line 800						
at Container->getDependencies(array(object(ReflectionParameter)), array()) in Container.php line 771						
at Container->build('SahraSalon\Http\Middleware\EncryptCookies', array()) in Container.php line 626						
at Container->make('SahraSalon\Http\Middleware\EncryptCookies', array()) in Application.php line 674						
.....

• solution: chạy command php artisan key:generate

Lỗi 2:

Whoops, looks like something went wrong

Warning: require(D:\xampp\htdocs\Laravel-5-Bootstrap-3-Starter-Site-master\bootstrap/../vendor/autoload.php): failed to open stream: No such file or directory in D:\xampp\htdocs\Laravel-5-Bootstrap-3-Starter-Site-master\bootstrap\autoload.php on line 17

Fatal error: require(): Failed opening required 'D:\xampp\htdocs\Laravel-5-Bootstrap-3-Starter-Site-master\bootstrap/../vendor/autoload.php' (include_path='D:\xampp\php\PEAR') in D:\xampp\htdocs\Laravel-5-Bootstrap-3-Starter-Site-master\bootstrap\autoload.php on line 17

• solution: kiểm đã có file .env trong thư mục source gốc chưa, có thể chạy lệnh php artisan key:generate

Lỗi 3:

Unexpected Exception: SQLSTATE[HY000] [1045] Access denied for user ****@'localhost' (using password: YES)

• solution: kiểm tra lại lại thông tin connection DB_USERNAME, DB_PASSWORD trong file .env hoặc trong config/database.php

Lỗi 4:

  [ReflectionException]
  Class UsersTableSeeder does not exist

• bạn vừa tạo 1 class , check đi check lại thấy đúng đường dẫn, đúng tên, đúng đuôi file, mà vẫn báo lỗi này thì câu lệnh sau có thể giúp bạn composer dump-autoload

Lỗi 5:

TokenMismatchException in VerifyCsrfToken.php line 68:

• chưa có token trong form khi submit, thêm code sau vào <form>...</form>

{{ csrf_field() }}

• chưa có token khi gửi ajax jquery , cài đặt axjax header:

$.ajaxSetup({
                headers: {
                    'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
                }
            });

Lỗi 6:

NotFoundHttpException in RouteCollection.php

• lỗi thư mục không có quyền

sudo chmod -R 777 storage
sudo chmod -R 777 bootstrap/cache

Lỗi 7:

[Illuminate\Database\QueryException] SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

• sửa trong file AppServiceProvider.php

use Illuminate\Support\Facades\Schema;
.....
public function boot()
{
Schema::defaultStringLength(191);
}