Fatal error: Uncaught Error: Class 'Symfony\Component\Mime\Header\UnstructuredHeader' not found in /opt/lampp/htdocs/us/vendor/symfony/mime/Header/ParameterizedHeader.php:19 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/us/vendor/symfony/mime/Header/ParameterizedHeader.php on line 19