Today, after a long pause, I decided to update my Home Assistant. My setup runs fully dockerised using Container Station on a QNAP NAS. As I had not restarted the NAS for a number of weeks I also took the opportunity to update all apps on the NAS including Container Station.

When I restarted, the MariaDB which is also dockerised, would not start. After 2 hours back and forth, I decided to create a new DB based on MYSQL and eventually Home Assistant was back up and running. That is except for a few irritating issues.

I have a number of mobile devices that I use for device tracking and apart from one (my main device) they have all initialised with no problem. The error that I get for the my device is shown below.

Logger: homeassistant.config_entries
Source: config_entries.py:402
First occurred: 8:12:10 PM (1 occurrences)
Last logged: 8:12:10 PM

Error setting up entry Pixel 6a for mobile_app
Traceback (most recent call last):
File “/usr/src/homeassistant/homeassistant/config_entries.py”, line 402, in async_setup
result = await component.async_setup_entry(hass, self)
File “/usr/src/homeassistant/homeassistant/components/mobile_app/init.py”, line 104, in async_setup_entry
webhook_register(hass, DOMAIN, registration_name, webhook_id, handle_webhook)
File “/usr/src/homeassistant/homeassistant/components/webhook/init.py”, line 53, in async_register
raise ValueError(“Handler is already defined!”)
ValueError: Handler is already defined!

Any ideas what the problem could be?

How long? You may be experiencing a breaking change. I would bet money your db issue was due to this considering deleting db (starting fresh with MySQL) seem to fix it. Incremental update may have worked.

Look like there is duplicate value. Does it cause and actual issue or you only notice the error in log. I would be tempted to unregister the pixel >> reboot >> verify error gone >> register pixel

It seems the reboot of the Pixel did the trick. Now device tracking is working again.

Regarding the problems with the MariaDB. The problems there started when I updated the NAS before moving to a newer Home Assistant version. I have read that Maria DB has issues with newer versions of Docker, so that could have been a possible cause.