Fatal error: Uncaught Error: Class "Symfony\Component\Notifier\FlashMessage\AbstractFlashMessageImportanceMapper" not found in I:\www\picman\vendor\symfony\notifier\FlashMessage\BootstrapFlashMessageImportanceMapper.php:19 Stack trace: #0 {main} thrown in I:\www\picman\vendor\symfony\notifier\FlashMessage\BootstrapFlashMessageImportanceMapper.php on line 19