ReflectionClass错误。将laravel 5.1升级到5.8

Question

我正在关注https://medium.com/@info.subashthapa/upgrading-laravel-5-0-to-5-8-1bfec5c8a0e2

现在将laravel 5.1升级到laravel 5.8

PHP Fatal error:  Uncaught ReflectionException: Class App\Console\Kernel does not exist in D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php:741
Stack trace:
#0 D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php(741): ReflectionClass->__construct('App\\Console\\Ker...')
#1 D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php(631): Illuminate\Container\Container->build('App\\Console\\Ker...', Array)
#2 D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Foundation\Application.php(674): Illuminate\Container\Container->make('App\\Console\\Ker...', Array)
#3 D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php(220): Illuminate\Foundation\Application->make('App\\Console\\Ker...', Array)
#4 D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php(738): Illuminate\Container\Container->Illuminate\Container\{closure}(Object(Illuminat in D:\xampp\htdocs\cloud\vendor\laravel\framework\src\Illuminate\Container\Container.php on line 741

我发现了ReflectionClass；在新鲜的laravel 5.8中，但我没有得到。

我从服务器下载composer.json，我惊讶其文件包含无效的json 。我不知道怎么回事。

我尝试将composer.json复制到替换旧 composer.json，但仍然出现错误ReflectionClass错误。

请建议我。