Fatal error: Uncaught Error: Class 'Symfony\Component\Mime\Header\AbstractHeader' not found in /home/bienalsurweb/public_html/convocatoria2021/vendor/symfony/mime/Header/DateHeader.php:19 Stack trace: #0 {main} thrown in /home/bienalsurweb/public_html/convocatoria2021/vendor/symfony/mime/Header/DateHeader.php on line 19