Fatal error: Uncaught Error: Interface "Psr\EventDispatcher\StoppableEventInterface" not found in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-core/Classes/Security/ContentSecurityPolicy/Event/PolicyMutatedEvent.php:26 Stack trace: #0 {main} thrown in /home/rcmch/test.m-s-i.ch/vendor/typo3/cms-core/Classes/Security/ContentSecurityPolicy/Event/PolicyMutatedEvent.php on line 26