Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\Client" not found in E:\xampp\htdocs\key1\vendor\symfony\http-kernel\Tests\Fixtures\TestClient.php:16 Stack trace: #0 {main} thrown in E:\xampp\htdocs\key1\vendor\symfony\http-kernel\Tests\Fixtures\TestClient.php on line 16