Fatal error: Uncaught Error: Class 'Symfony\Component\HttpKernel\DependencyInjection\Extension' not found in C:\xampp\htdocs\admin\vendor\symfony\http-kernel\DependencyInjection\ConfigurableExtension.php:28 Stack trace: #0 {main} thrown in C:\xampp\htdocs\admin\vendor\symfony\http-kernel\DependencyInjection\ConfigurableExtension.php on line 28