500 Internal Server Error setting up ZHA with SLZB-06

I get this error when trying to add the ZHA integration for SLZB-06:

UI: Unknown error occurred
Console:

fetch-with-auth.ts:20 POST http://homeassistant.local:8123/api/config/config_entries/flow/01JY9AC385Z0X03JY8237GFB9D 500 (Internal Server Error)

HA

  • Installation methodHome Assistant OS
  • Core2025.6.1
  • Supervisor2025.05.5
  • Operating System15.2
  • Frontend20250531.3

SLZB-06

  • core firmware: v2.9.2 (up-to-date)
  • zigbee firmware: 20221226 (up-to-date)

Any ideas?

Upgrade the zigbee firmware to 20240710 or at least 20230507. 20221226 is for sure not the latest.

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In that case, I’m not seeing the latest in the UI. I’m seeing this instead. Any idea how to force a refresh?

SLZB-06 Zigbee firmware Up-to-date

Installed version
20221226

Latest version
20221226

Don’t have a SLZB-06 myself, I know LiQuid_cOOled runs 20240710 on his.

check here:

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I always use the SLZB’s built-in UI for firmware updates. It’s accessible via the device’s IP or http://slzb-06

Go to Settings and Tools and select Firmware Update

I currently running Firmware version: 20250325 with v2.9.2

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I’ve updated via the web interface for the device (thanks for the suggestion!).

It now reads:
Firmware: core: v2.9.2 / zigbee: 20250325

Unfortunately this does not solve the problem - I still see the same 500 internal server error when setting up ZHA.

Try restarting HA first

Ok, I restarted HA, which seemed to get me a bit further in the process, but ultimately I still ended with the same error. I’m wondering if I’ve setup auth on something that I shouldn’t have. Not sure, but digging in.

Longshot, but you don’t have Zigbee2mqtt installed?

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This was a great shout. I didn’t have Zigbee2MQTT installed, but I did have the Mosquito Broker Add-on. Removing that, fixed it. Thank you!