Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Mapping\Loader\LoaderChain" not found in C:\Apache24\htdocs\cw\vendor\symfony\validator\Mapping\Loader\FilesLoader.php:23 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cw\vendor\symfony\validator\Mapping\Loader\FilesLoader.php on line 23