Fatal error: Uncaught Error: Interface "TYPO3\CMS\Core\Mail\MailerInterface" not found in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/Mail/Mailer.php:38 Stack trace: #0 {main} thrown in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/Mail/Mailer.php on line 38