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Version: 1.2.0

Troubleshooting

Connection issues​

MQTT won't connect to external broker​

Usually this problem arises from an improperly configured network.

  • Make sure, the external broker is available from the network you're running a smoothMQTT app in.
  • Your smoothMQTT app needs to have one MQTTManager prefab instance in the scene.
  • Confirm the IP address and Port on the settings component match the address and port of your broker.
  • Check if the broker's firewall accepts incoming connections on the MQTT port(s)
  • If it still doesn't work, restart the broker and restart the unity app.
  • NOTE: If you have a very slow network connection, you might want to increase connection timeout (on settings component) to above 3, however if this is necessary your MQTT experience will be far from realtime.

I can connect but neither send nor receive messages​

Check if the broker has user management and restrictions in place. Use proper username and password in settings component.

I can connect and either send or receive messages, but not both​

There are user restrictions in place in the broker configuration. Make sure the client user has access to all topics to be used.

Leading Slash in Topics​

This is a syntactical problem typically encountered in MQTT. The topic /test/topic and test/topic are not the same. While both are valid, some other client not from your unity app (for example a sensor or a python script) might use URL-notation for MQTT where the second slash might be autoremoved, i.e. mqtt://user:password@hostname//test/topic does write to test/topic instead of /test/topic. This is very hard to find and debug, so my suggestion is to never use a leading slash in your topics.

Tools Menu does not do anything​

Check your console for any warnings. If it says "No Gameobject selected" you need to select a gameobject in your scene or hierarchy before trying to add the components.