405 Not Allowed on Updating HA Core

Good morning Hassians,
I am a bit puzzled by the following, when trying to update Home Assistant Core via Supervisor (current version: core-2021.2.3) to version core-2021.3.0 I am getting a strange 405 Not Allowed error message inside the update panel. See attached screenshot as well.
Screen Shot 2021-03-04 at 09.34.47

Searching github and these community boards I could not find any clue where to look for resolving this. I tried connecting through my local url (https://192.168.x.x:port) and via the external url (via Synology’s reverse proxy and https), but the error keeps popping up. The rest of HA works all fine.
In addition: when trying to install a new add-on (room-assistant) the same error appears, so it might not be solely linked to the HA core update.

What should be my next steps to fix this 405?

What is in the supervisor log? Which version of docker are you running? Did you do a host update recently?

Hi David, good morning!
I am running supervisor-2021.03.3 on Home Assistant OS 5.12 (Raspberry pi 4).
Also nothing crazy going on in the supervisor log, here’s the latest after initiating the update;

21-03-04 08:33:20 INFO (MainThread) [supervisor.snapshots] Creating new partial-snapshot with slug b3087411
21-03-04 08:33:20 INFO (MainThread) [supervisor.snapshots] Snapshotting b3087411 store folders
21-03-04 08:33:20 INFO (SyncWorker_5) [supervisor.snapshots.snapshot] Snapshot folder homeassistant
21-03-04 08:33:21 INFO (MainThread) [supervisor.homeassistant.websocket] WebSocket command WSType.SUPERVISOR_EVENT is not supported untill core-2021.2.4. Ignoring WebSocket message.
21-03-04 08:33:28 INFO (SyncWorker_5) [supervisor.snapshots.snapshot] Snapshot folder homeassistant done
21-03-04 08:33:28 INFO (MainThread) [supervisor.snapshots] Creating partial-snapshot with slug b3087411 completed
21-03-04 08:33:28 INFO (MainThread) [supervisor.homeassistant.websocket] WebSocket command WSType.SUPERVISOR_EVENT is not supported untill core-2021.2.4. Ignoring WebSocket message.
21-03-04 08:33:28 INFO (MainThread) [supervisor.homeassistant.core] Updating Home Assistant to version 2021.3.0
21-03-04 08:33:28 INFO (SyncWorker_0) [supervisor.docker.interface] Updating image homeassistant/raspberrypi4-homeassistant:2021.2.3 to homeassistant/raspberrypi4-homeassistant:2021.3.0
21-03-04 08:33:28 INFO (SyncWorker_0) [supervisor.docker.interface] Downloading docker image homeassistant/raspberrypi4-homeassistant with tag 2021.3.0.

What are the next few lines in the supervisor log?
Also answers to other questions…

Apparently the update did install (but took a very long time). Here’s how the log continues;

21-03-04 08:49:46 INFO (SyncWorker_0) [supervisor.docker.interface] Stopping homeassistant application
21-03-04 08:50:01 INFO (SyncWorker_0) [supervisor.docker.interface] Cleaning homeassistant application
21-03-04 08:50:02 INFO (MainThread) [supervisor.homeassistant] Update pulse/client.config: /data/tmp/homeassistant_pulse
21-03-04 08:50:08 INFO (SyncWorker_5) [supervisor.docker.homeassistant] Starting Home Assistant homeassistant/raspberrypi4-homeassistant with version 2021.3.0
21-03-04 08:50:08 INFO (MainThread) [supervisor.homeassistant.core] Wait until Home Assistant is ready
21-03-04 08:54:16 INFO (MainThread) [supervisor.homeassistant.core] Detect a running Home Assistant instance
21-03-04 08:54:16 INFO (MainThread) [supervisor.homeassistant.core] Successful started Home Assistant 2021.3.0
21-03-04 08:54:17 INFO (SyncWorker_4) [supervisor.docker.interface] Cleanup images: ['homeassistant/raspberrypi4-homeassistant:2021.2.3']

But still no insights in where the 405 came from.

So something is stopping HA from starting so it rolls back. This is probably a custom component. What is in the HA log?

Well actually HA is starting and working fine. Now trying again to install add-on Room-assistant, to see if the 405 comes up again… result: no installs just fine…

Here’s the HA log, thanks for hanging in @DavidFW1960

2021-03-04 09:50:14 WARNING (MainThread) [homeassistant.loader] You are using a custom integration hacs which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-03-04 09:50:14 WARNING (MainThread) [homeassistant.loader] You are using a custom integration circadian_lighting which has not been tested by Home Assistant. This component might cause stability problems, be sure to disable it if you experience issues with Home Assistant
2021-03-04 09:50:14 WARNING (MainThread) [homeassistant.loader] No 'version' key in the manifest file for custom integration 'circadian_lighting'. This will not be allowed in a future version of Home Assistant. Please report this to the maintainer of 'circadian_lighting'
2021-03-04 09:50:49 ERROR (MainThread) [homeassistant] Error doing job: protocol.resume_writing() failed
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/asyncio/transports.py", line 294, in _maybe_resume_protocol
    self._protocol.resume_writing()
  File "/usr/local/lib/python3.8/asyncio/sslproto.py", line 517, in resume_writing
    self._app_protocol.resume_writing()
  File "/usr/local/lib/python3.8/site-packages/aiohttp/base_protocol.py", line 31, in resume_writing
    assert self._paused
AssertionError

The thing is supervisor log shows it times out and then it rolls back to previous and starts again so you have to catch the log before it restarts.
It will be a custom component causing it to hang.
When you have a real log (before it rolls back and restarts) you will know what the issue is.