Fatal error: Uncaught Error: Class "TYPO3\CMS\Frontend\ContentObject\AbstractContentObject" not found in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-frontend/Classes/ContentObject/CaseContentObject.php:21 Stack trace: #0 {main} thrown in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-frontend/Classes/ContentObject/CaseContentObject.php on line 21