Fatal error: Uncaught Error: Interface "Psr\EventDispatcher\EventDispatcherInterface" not found in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/EventDispatcher/EventDispatcher.php:29 Stack trace: #0 {main} thrown in /var/www/html/dev.hallescherfc.de/vendor/typo3/cms-core/Classes/EventDispatcher/EventDispatcher.php on line 29