Fatal error: Uncaught Error: Interface "Ratchet\Wamp\WampServerInterface" not found in /users/energydata/www/volkszaehler.org/lib/Server/WampClientAdapter.php:32 Stack trace: #0 {main} thrown in /users/energydata/www/volkszaehler.org/lib/Server/WampClientAdapter.php on line 32