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