Zigbee2MQTT add-on stopped

Configuration
1

My Zigbee2MQTT stopped and wont restart. I get
error 502- Bad Gateway

I reinstalled the add-on and get the same results.

Looking at the add-on log, I see this:

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
            READ THIS CAREFULLY

Refusing to start because configuration is not valid, found the following errors:
- MQTT retention requires protocol version 5

If you don't know how to solve this, read https://www.zigbee2mqtt.io/guide/configuration

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

But there is nothing in the configuration guide about “protocol version 5”

I restored a backup from two days ago when I knew Zigbee devices were working, and got the same results.

I also tried using a different MQTT broker- same results.

Any tips would be appreciated.

2

I suspected a bad Zigbee dongle and tried adding the ZHA integration. It immediately started finding all of my devices, so the dongl is working. I don’t recall why I originally chose to use use Zigbee2Mqtt over ZHA, but all of my Zigbee devices are working in ZHA. Now all I need to do is rewrite a few automations.