Fatal error: Uncaught Error: Interface "Psr\Http\Server\MiddlewareInterface" not found in /var/www/html/dev.hallescherfc.de/vendor/in2code/femanager/Classes/Middleware/CleanUserGroupMiddleware.php:12 Stack trace: #0 {main} thrown in /var/www/html/dev.hallescherfc.de/vendor/in2code/femanager/Classes/Middleware/CleanUserGroupMiddleware.php on line 12