Fatal error: Uncaught Error: Interface "JMS\Serializer\Handler\SubscribingHandlerInterface" not found in /home/gingerbrup/rappelapi/vendor/jms/serializer-bundle/Tests/DependencyInjection/Fixture/SubscribingHandler.php:8 Stack trace: #0 {main} thrown in /home/gingerbrup/rappelapi/vendor/jms/serializer-bundle/Tests/DependencyInjection/Fixture/SubscribingHandler.php on line 8