Update to 18.3 failed

Installation Home Assistant OS
1

Running bare metal on an intel NUC.
Tried updating to 18.3 and it spent hours with nothing happening.
Internet connectivity is working fine as is DNS resolution
Using the CLI I see the following errors in the log:

2026-09-19 10:06:01.790 ERROR (MainThread) [supervisor.os.manager] Can't fetch OTA update from https://os-artifacts.home-assistant.io/18.3/haos_generic-x86-64-18.3.raucb: 
2026-09-19 10:06:01.797 ERROR (MainThread) [supervisor.api.utils] Unexpected error during API call: Can't fetch OTA update from https://os-artifacts.home-assistant.io/18.3/haos_generic-x86-64-18.3.raucb: 
Traceback (most recent call last):
  File "/usr/local/lib/python3.14/site-packages/aiohttp/streams.py", line 365, in _wait
    await waiter
asyncio.exceptions.CancelledError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/supervisor/supervisor/os/manager.py", line 221, in _download_raucb
    chunk = await request.content.read(1_048_576)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/aiohttp/streams.py", line 448, in read
    await self._wait("read")
  File "/usr/local/lib/python3.14/site-packages/aiohttp/streams.py", line 364, in _wait
    with self._timer:
         ^^^^^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/aiohttp/helpers.py", line 759, in __exit__
    raise asyncio.TimeoutError from exc_val
TimeoutError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/src/supervisor/supervisor/api/utils.py", line 146, in wrap_api
    answer = await method(*args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/supervisor/supervisor/api/os.py", line 186, in update
    await asyncio.shield(self.sys_os.update(version))
  File "/usr/src/supervisor/supervisor/jobs/decorator.py", line 370, in wrapper
    return await execute()
           ^^^^^^^^^^^^^^^
  File "/usr/src/supervisor/supervisor/jobs/decorator.py", line 313, in execute
    raise err
  File "/usr/src/supervisor/supervisor/jobs/decorator.py", line 305, in execute
    return await method(obj, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/supervisor/supervisor/os/manager.py", line 382, in update
    await self._download_raucb(ota_url, int_ota)
  File "/usr/src/supervisor/supervisor/os/manager.py", line 234, in _download_raucb
    raise HassOSUpdateError(
        f"Can't fetch OTA update from {url}: {err!s}", _LOGGER.error
    ) from err
supervisor.exceptions.HassOSUpdateError: Can't fetch OTA update from https://os-artifacts.home-assistant.io/18.3/haos_generic-x86-64-18.3.raucb:
2

Hi, You say nothing in regards to your system ver. prior to update: Settings/ About !
Also you don’t tell whether you have perform" yet another" ReBoot ( just as precaution )

And apparently you can access the CLI , but can you access UI ?, again what says Setting/About

3

Apologies, here is the system info:

System version: 18.2
Core: 2026.9.3
Supervisor: 2026.09.2
Frontend: 20260826.7

System is working perfectly I can access UI, use terminal from HA or SSH.
Recently updated core and supervisor with no problems.

Rebooted several times, first when the updated via UI did not work, tried to update again from UI, still did not work. Rebooted again then tried update from CLI, did not work either.
Checked internet connectivity and DNS resolution, rebooted and tried update from CLI again, still did not work.
That’s when I posted the message on the forum (and now I realise I left out a lot of info)

4

Thanks, Yes that’s the first thought people sitting with, when reading such an “issue” :slight_smile:

I just finished my Update, when i saw your Post, everything went smooth here, and i always check my logs prior to such “major” installs
Sorry i can’t be of more help here.
Other than check your firewall/DNS “Blocks or Filters” and/or try again later (if it’s caused by Github being “busy”)
Meaning, i.e also disable Add-blockers, and try with i.e 1.1.1.1 in your DNS settings, as This “service” if any should have latest DNS-records( as it’s HA’s default Fallback)

5

“lightbulb” moment re: your comment on firewall.
I have Suricata running on my firewall and buried in the logs I found this:

ET INFO Github CDN for Release Assets Domain in DNS Lookup (release-assets .githubusercontent .com)

Disabled the alert and unblocked the relevant IP addresses and now the update works.

A clear case of RAOTFL (read all of the f*ing logs!)

Thanks for you interest. You put me on the right track after a late night and early morning trying to find out why the update failed.

6

Great that you are “aware” to quick responds and troubleshooting procedures, when getting “feedback” :slight_smile:
You should have taken a “bedrunner” last night, instead of sitting up :grin:

PS: With HA i also learned (specifically lately) , don’t run an OS/Core update, if your don’t have time or are in the “mood” for a rollback/or hours of troubleshooting/editing :laughing: … My reason of doing this update, this morning over my coffee , now i have the whole Day to do … ehh …something

7

Perhaps adding the solution tag to the appropriate post would be in order to allow this post to close appropriately.

8

I had the same issue.
The update ran forever.

Snort was blocking calls to GitHub.
The Suricata mention gave me the idea to check my Snort alerts and blocked IPs; sure enough, there it was.

Thank you.