Fatal error: Uncaught Error: Class "TYPO3\CMS\Core\Messaging\AbstractMessage" not found in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-core/Classes/Messaging/FlashMessage.php:26 Stack trace: #0 {main} thrown in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-core/Classes/Messaging/FlashMessage.php on line 26