mqtt error 16 during publish

[ttadam]

Hello there,

Well, I stuck therefore I ask some help from the community. I have an esp32, what sends to an mqtt server, and after a few (like 5 or 6) publish I receive an error 16, and after that that is the only thing what happening every time when the board wants to publish.
Did some digging, I found here that 16 means "Malformed received MQTT packet . I don't really know what does that mean, or how to prevent it.

Thanks in advance!

[pythoncoder]

I suggest you tell us which MicroPython MQTT library you're using. Also what broker software you're running, and on what platform.

[ttadam]

I am using mqtt simple.
The server/Broker is emqx v4.

[pythoncoder]

Any chance of trying mosquitto for your broker to see if this has any effect? It's available in most Linux distros.

As far as I know all testing has been done using this. I've never seen this error.

[ttadam]

I think I got closer to the issue. It is not mqtt error 16, it is an OSError 16... and coming from the mqtt library from this line:
self.sock = ussl.wrap_socket(self.sock, **self.ssl_params)