Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Mapping\Loader\FilesLoader" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\Mapping\Loader\XmlFilesLoader.php:22 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\Mapping\Loader\XmlFilesLoader.php on line 22