Fatal error: Uncaught Error: Class "TYPO3Fluid\Fluid\Core\ViewHelper\AbstractTagBasedViewHelper" not found in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-extensionmanager/Classes/ViewHelpers/ToggleExtensionInstallationStateViewHelper.php:37 Stack trace: #0 {main} thrown in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-extensionmanager/Classes/ViewHelpers/ToggleExtensionInstallationStateViewHelper.php on line 37