Fatal error: Uncaught Error: Class "TYPO3\CMS\Core\Cache\Backend\AbstractBackend" not found in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/Cache/Backend/NullBackend.php:21 Stack trace: #0 {main} thrown in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/Cache/Backend/NullBackend.php on line 21