Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Mapping\Loader\LoaderChain" not found in /home/wizilen/www/vendor/symfony/validator/Mapping/Loader/FilesLoader.php:23 Stack trace: #0 {main} thrown in /home/wizilen/www/vendor/symfony/validator/Mapping/Loader/FilesLoader.php on line 23