Fatal error: Uncaught Error: Interface "Psr\Http\Server\RequestHandlerInterface" not found in /opt/lampp/htdocs/forum/flarum/vendor/middlewares/utils/src/RequestHandler.php:10 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/forum/flarum/vendor/middlewares/utils/src/RequestHandler.php on line 10