Fatal error: Uncaught Error: Class "Symfony\Component\Config\Loader\FileLoader" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\config\Loader\GlobFileLoader.php:19 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\config\Loader\GlobFileLoader.php on line 19