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