The problem here is that you are asking the same/similar question in many different places and as a result you are getting many different disparate answers because no one knows about the other conversations going on in 4 different threads.
I really think you need to just stick to using one thread to try to help you figure stuff out and things will be far less confusing for others who are trying to help you and especially for you trying to follow suggestions from 4 different threads at the same time.
This add-on is attached to the Home Assistant user system, so mqtt clients can make use of these credentials. Local users may also still be set independently within the configuration options for the add-on. For the internal Hass.io ecosystem we register ‘homeassistant’ and ‘addons’ , so these may not be used as user names.
I can see in your logs that indeed you have chosen the username “homeassistant”
Maybe that creates your trouble. I do not know if this constraint was added recently. I am not a dev. I just noted this and remember that you used that user name in your logs
The link provided relates to using the Mosquitto Addon and not Mosquitto on bare metal. I just wonder if the integration code with external could have similar issue. It is worth a try.
To change user name use the mosquitto_passwd application. You cannot just hack the user name in the password file
I wrote: “ The link provided relates to using the Mosquitto Addon and not Mosquitto on bare metal. I just wonder if the integration code with external could have similar issue. It is worth a try.”
Yeah, I get that but the OP is already confused enough and he’s posted this same problem to 3 or 4 threads and getting advice from many sources none of which necessarily knows about all of the others which is definitely making things worse.
I just wanted to be sure to point out to him that the problem that you posted is related to hassio not necessarily HA in a venv so there may be no need to be concerned about it yet.
What the OP needs to do is follow your advice and upgrade on a fresh, default configuration.yaml, and then reintroduce his personal config chunk by chunk.
I say your advice, because you posted it in one of the threads. I posted almost identical advice in one of the others.
The MQTT error is a big red herring at the moment, and trying to fix it is probably breaking more things.
Unfortunately, if the OP isn’t going to do this, everyone is wasting their time and we may as well merge and lock the threads.