Home Assistant 2026.9 not working correctly after the update? Here's what's going on

Updating to Home Assistant 2026.9, released on 2 September 2026, leaves some installations with a dashboard loading error, a restart loop, or a sharp spike in memory use. This is not a one-off fault in your own configuration; it matches known, currently reported problems with this specific release, confirmed by multiple users on the Home Assistant community forum.

The two cases below have a very different status: one already has a confirmed cause and a simple fix, the other is still open and has no official resolution as of when this guide was published (5 September 2026).

Symptoms: after updating, the dashboard shows "Could not load Home Assistant. Please refresh the page" in both the browser and the companion app, the interface feels slow, icons are missing, and opening Settings → Integrations produces an error. Logging in sometimes works, but the error returns after a refresh.

Reports from multiple users point to a specific cause: a leftover extra_module_url entry in configuration.yaml pointing to the HACS card-mod.js file. As of 2026.9.0 that entry is no longer needed and causes the interface loading error.

Confirmed fix: find an entry similar to extra_module_url: - /config/www/community/lovelace-card-mod/card-mod.js in configuration.yaml, comment it out or remove the line, then restart Home Assistant. Multiple users confirmed this fully resolves the issue.

Symptoms: Home Assistant starts, runs for roughly a minute, then restarts again in a loop. The logs show a sharp memory spike, in some reports reaching a full 9-10 GB of RAM used. The issue has been confirmed across different platforms, including Proxmox and Unraid, which points to a fault in the release itself rather than one specific setup.

As of when this guide was published, the Home Assistant team had not posted an official response or fix in the thread. Some users mention an unofficial hint that a patch release could follow shortly, but this is not confirmed by the team.

Reported workarounds: rolling back to 2026.8.3 does not always help, and Safe mode does not always remove the issue either. The only approach described in the thread as reliable is a fresh installation with a backup restored from before the update.

If you have not yet updated a production system and do not have to right now, consider waiting for a follow-up patch release. If you are already seeing this symptom, preserve the current logs and avoid further trial-and-error changes; the general, safe troubleshooting order for any update is covered in the Home Assistant not working after an update guide.

If you have not updated yet, the official release notes list several changes that may affect your installation:

• UniFi Protect: the integration now requires version 7.2.105 or newer.
• Updates: installing, skipping, and clearing updates now requires an administrator account.
• Vacuum entities: the deprecated battery_level property has been removed; battery level needs a separate sensor.
• Z-Wave JS: managing lock users and credentials now requires an administrator account.
• A few smaller changes also affect the Flexit Nordic integration, KNX expose behaviour, and LLM API tool names; check the full official release notes before updating a larger installation.

Home Assistant creates an automatic backup before every update by default, but it is worth checking its date and scope yourself before clicking "Update", especially on a larger or production installation. Preparing and restoring backups is covered in the Home Assistant backup guide.

I can remotely check whether your case matches a known issue with this release or something specific to your setup, and choose a safe way to fix it.

• Home Assistant: official 2026.9 release notes
• Home Assistant: full 2026.9 changelog
• Community thread: "Could not load Home Assistant" after updating to 2026.9.0
• Community thread: constant reboot after the 2026.9 update