Fatal error: Uncaught Error: Class "Symfony\Component\DependencyInjection\Extension\Extension" not found in D:\Application\www\E-Tracking\vendor\symfony\http-kernel\DependencyInjection\Extension.php:21 Stack trace: #0 {main} thrown in D:\Application\www\E-Tracking\vendor\symfony\http-kernel\DependencyInjection\Extension.php on line 21