Since 11 October 2026, resetting a Home Assistant Green from an SD card has failed for anyone using the installer linked in Nabu Casa's support guide. According to the pull request that updated the guide, the old image, green-installer-20240410, stops at curl: (6) Could not resolve host: version.home-assistant.io whatever DNS server the network hands out, so it never downloads Home Assistant OS.
The cause: a new root key
On 11 October the DNS root zone switched signing keys. IANA's schedule shows KSK-2024 taking over from KSK-2017 that day, and from then on a validating resolver needs the new trust anchor to check answers from the root. The 2024 installer ships systemd 252, whose resolver only knows the old key, so DNSSEC validation fails and no name resolves. The pull request says the image has failed on every Green since the rollover.
The fix
Nabu Casa published Build 20261015 of its buildroot-installer on 15 October (20:33 UTC). It moves to buildroot 2025.02.18 and systemd 256.17, which carries both root keys. The release contains two images: green_installer-20261015.img.xz for the Green and yellow_installer-20261015.img.xz for the Yellow. The new file name uses an underscore instead of a hyphen, which is worth knowing if you search for it.
The support article "Resetting Home Assistant Green using an SD card" now links the new image. The change by Ashton (cogneato) was merged on 16 October. The procedure is the same as before: write the image with Balena Etcher, shut the Green down, push the card in until it clicks, power on with the network connected, wait for the LEDs to go out, remove the card and power on again.
One caveat from the pull request: when it was merged, support had not yet seen a completed reset with the new image on a Green. Two customers with the failure had just been sent it.
Who needs to act
This only matters if you reset or reinstall a Green from an SD card. The report says nothing about installations that are already running. If you keep a recovery card in a drawer, or a saved copy of the old guide, rewrite the card with the October image. The Yellow got a new installer in the same release, although the support change only covers the Green.