Fatal error: Uncaught Error: Class 'Symfony\Component\Mime\Header\UnstructuredHeader' not found in /home/acb20f5/public_html/alp/vendor/symfony/mailer/Header/MetadataHeader.php:19 Stack trace: #0 {main} thrown in /home/acb20f5/public_html/alp/vendor/symfony/mailer/Header/MetadataHeader.php on line 19