# MQTT Distributor 4.0.3 (b2020012800): NettyMQTTHandler Ugly error on networking **URL:** \ **Category:** 3rd Party Modules\ **Created:** [February 8, 2021, 7:10pm UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141 "2021-02-08T19:10:58Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mudbay](https://avatars.discourse-cdn.com/v4/letter/m/a4c791/32.png) [@mudbay](https://forum.inductiveautomation.com/u/mudbay)\ **Post date:** [February 8, 2021, 7:10pm UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/1 "2021-02-08T19:10:58Z")
Not sure if this is the right forum for this question, but I have installed an MQTT Distributor on a Windows 10 box (with Gateway installed v. 8.1). When I enable the MQTT Distributor, I get an error thrown in the logger. Error: **NettyMQTTHandler Ugly error on networking** Does anyone have some guidance on where I can find additional info on this error? BTW: I have firewall settings open so there should not be any port blocking. Also, I ran the MQTT.FX utility locally and remotely and the Pub/Sub seems to work with this tool. But the remote MQTT Transmission will not show connected. So it is partially working. More Detail in terms of general architecture under test: ![MQTT Architecture vDev](https://us1.discourse-cdn.com/inductiveautomation/original/3X/c/e/ce0ea61e15fb522bf1bb6dad4ab77f91faa4b048.jpeg) ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [February 8, 2021, 7:18pm UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/2 "2021-02-08T19:18:47Z")
Paging @wes0johnson ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [February 8, 2021, 7:47pm UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/3 "2021-02-08T19:47:43Z")
Generally that error is the result of some MQTT client sending a non-MQTT compliant packet or from an unclean disconnect of an MQTT client. I would suggest sending an email with this context and zipped up Ignition logs to [support@cirrus-link.com](mailto:support@cirrus-link.com) so we can figure out exactly what is causing it. ---
**Author:** ![mudbay](https://avatars.discourse-cdn.com/v4/letter/m/a4c791/32.png) [@mudbay](https://forum.inductiveautomation.com/u/mudbay)\ **Post date:** [February 8, 2021, 9:46pm UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/4 "2021-02-08T21:46:09Z")
> [@wes0johnson](#): > > [support@cirrus-link.com](mailto:support@cirrus-link.com) Thanks Wes, I will forward what I have on this. Cheers, Chris ---
**Author:** ![mudbay](https://avatars.discourse-cdn.com/v4/letter/m/a4c791/32.png) [@mudbay](https://forum.inductiveautomation.com/u/mudbay)\ **Post date:** [February 9, 2021, 12:07am UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/5 "2021-02-09T00:07:41Z")
@wes0johnson: I think I managed to find out what the issue was with the setup. Thankfully I caught this before wasting a lot of people’s time. I noticed that the MQTT Distributor is running on 8.1.2 version of Ignition where as the MQTT Transmission and Engine were both running on 8.1.0 versions. After I upgraded, the exception in the Logger has seemed to gone away. (I will monitor for a while to see). Does that make sense that all Ignition versions need to be the same? ---
**Author:** ![wes0johnson](https://avatars.discourse-cdn.com/v4/letter/w/7ab992/32.png) [@wes0johnson](https://forum.inductiveautomation.com/u/wes0johnson)\ **Post date:** [February 9, 2021, 12:35am UTC](https://forum.inductiveautomation.com/t/mqtt-distributor-4-0-3-b2020012800-nettymqtthandler-ugly-error-on-networking/43141/6 "2021-02-09T00:35:54Z")
Hmmm - that is odd. I can’t think of why this would be the case. There are some requirements with regard to version compatibility ([https://docs.chariot.io/display/CLD80/Version+Compatibility](https://docs.chariot.io/display/CLD80/Version+Compatibility)). But, there isn’t anything that I can think of with your versions that would’ve caused an issue. Let us know if anything else comes up.