Failing with Connection Return Codes 7

I have been testing a python client (Paho) with my local MQTT server (windows 10). It is working fine with passwords and TLS as well.

My Paho python client successfully connects to HiveMQ public mosquito broker using port 1883 without any issues as well!

But when I tried to connect to my hiveMQ cloud broker using port 8883, it fails to connect to the broker with return code 7. According to my understanding MQTT Connection Return Codes are only defined up to 5, can someone explain what causes this error?

I successfully connected to the cloud broker using my Linux mosquito broker using the following command

mosquitto_sub -h f86f3a7384644b569094607fbe400e2e.s2.eu.hivemq.cloud -p 8883 -u manoj2 -P my_PASSWORD -t my/test/topic

But when I tried the same command on the windows 10 mosquito broker it returns the following error

Error: protocol error

Hi @acmmanoj ,

Great that you are interested in MQTT and HiveMQ, welcome to the community!

Are you following this Getting started with Paho Python guide? If so, please indicate which steps of the guide did work correctly for you and at which step you are stuck now.

Tnx,
Dasha from HiveMQ team

@Daria_H

Thanks for the replay. The problem was sorted out. When the TLS certificate is included with the python client, messaging service starts normally. It seems that Ubuntu allows communication with HiveMQ mosquito broker without the certificate whereas Windows no.

Manoj