Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\HttpKernel" not found in E:\xampp\htdocs\key1\vendor\symfony\http-kernel\Tests\TestHttpKernel.php:21 Stack trace: #0 {main} thrown in E:\xampp\htdocs\key1\vendor\symfony\http-kernel\Tests\TestHttpKernel.php on line 21