Symfony 5 Messenger not auto configuring message handler

  symfony, symfony-messenger, symfony5

I am new to Symfony framework and am trying to set up a project with Messenger ( My understanding is after setting up the handler class with “implements MessageHandlerInterface” the handler should be available for use but it does not seem to be working for me. I have tried several different things including setting up a new project from scratch. I am using Symfony 5.0.4.

I set up the project like this:

symfony new --full testMessenger
composer require messenger
php bin/console make:controller

Then I made a new messenger and handler and called it from the controller. Doing that I get the exception: “No handler for message “AppMessageMessage”.

php bin/console debug:messenger




The following messages can be dispatched: 

     handled by mailer.messenger.message_handler       
     handled by chatter.messenger.chat_handler         
     handled by texter.messenger.sms_handler           

My code is basically the same as the samples in the message handler documentation, but I will add it here.

// src/Message.php

namespace AppMessage;

class Message
    private $content;

    public function __construct(string $content)
        $this->content = $content;

    public function getContent(): string
        return $this->content;

// src/MessageHandler.php

namespace AppMessageHandler;

use AppMessageMessage;
use SymfonyComponentMessengerHandlerMessageHandlerInterface;

class SmsNotificationHandler implements MessageHandlerInterface
    public function __invoke(Message $message)
        // ... do some work - like sending an SMS message!

// src/Controller/MessageController.php

namespace AppController;

use SymfonyBundleFrameworkBundleControllerAbstractController;
use SymfonyComponentRoutingAnnotationRoute;
use AppMessageMessage;

class MessageController extends AbstractController
     * @Route("/message", name="message")
    public function index()
        $this->dispatchMessage(new Message('Look! I created a message!'));

        return $this->render('message/index.html.twig', [
            'controller_name' => 'MessageController',

Source: Symfony Questions