MQTT broker confusion in OH3

I’m coming from OH2.5 where I used the 1.x MQTT binding with an external Mosquitto broker.
After a lot of research I found that you need to create a bridge Broker and a Generic MQTT thing and then add channels for each topic. A bit complex to setup, but it works.

Now somehow I also have a “MQTT system broker connection” at the Settings page.

What does this MQTT system broker do, and do I need to configure it?

It keeps complaining about the host/IP not being setup, but looks like I don’t need this? How can I can rid of this entry?
2020-12-22 12:04:14.458 [WARN ] [.MqttBrokerConnectionServiceInstance] - MqttBroker connection configuration faulty: host : You need to provide a hostname/IP!

I think that’s a way to set up a “default” MQTT broker connection. You don’t need to do anything there if you create Broker Things. But I’m not really sure. I haven’t messed with it.

Have you edited or even just clicked “save” from that menu? You do need the host/IP to have a valid MQTT connection to a broker. If you’ve clicked save, perhaps it generated an empty config and that’s what it is complaining about. You can see if you have a $OH_USERDATA/config/org/openhab/mqtt.config file. If so try stopping OH and deleting it.

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See post nov 29.

Edit: after that, the error message in you log should be gone. Zet hem op :slight_smile:

Thanks, it lead me to the solution.
In my case it was the file mqttbroker.config in that $OH_USERDATA/config/org/openhab/ dir (created over a year ago) that was causing the error to show. Deleted it and all is fine now.

@Qwerty_Zet I tried your solution too, in my case it didn’t solve it. Toch bedankt!

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Although I have just installed it, I did not have any settings. I did what you said above. not resolved. Why don’t the friends who write OH3 see these problems and offer suggestions for solutions?

My issue was an error in the log, not an empty settings page.
Did you install the MQTT binding?