Home Assistant 2026.9 Says “Could Not Load Home Assistant”? Here’s the Actual Fix
A blank “Could not load Home Assistant. Please refresh the page” screen after updating to 2026.9 is almost always caused by one leftover line. It’s an old extra_module_url entry pointing at the HACS card-mod script. Home Assistant 2026.9 stopped needing that line, and its presence now breaks the frontend instead of just being ignored. Comment it out, restart, and the dashboard loads again for most people. If it doesn’t, the fixes further down cover the less common causes.
Home Assistant 2026.9 rolled out on September 2, 2026, and within days the community forum and GitHub issue tracker filled up with the same complaint: a white screen or a banner reading “Could not load Home Assistant. Please refresh the page.” Refreshing does nothing. The companion app shows the identical message. Settings → Integrations either won’t open or throws an error on top of it.
Why Does Home Assistant 2026.9 Show This Error?
The frontend loading error traces back to a single deprecated setting: extra_module_url inside configuration.yaml. It’s typically left over from an older HACS install of card-mod, back when Lovelace needed you to manually register the resource file yourself. As of 2026.9.0, that manual registration path was retired. The frontend no longer expects the entry, and instead of quietly skipping it, it fails to build the dashboard at all.
When I checked the GitHub issue thread on home-assistant/core, dozens of reports converged on the same line: extra_module_url: - /config/www/community/lovelace-card-mod/card-mod.js. Not everyone has that exact path. Some installs point at a different HACS frontend card, but the pattern — an extra_module_url block referencing a community card — is consistent across almost every report.
This part trips a lot of people up because the config technically “worked” for years. It only breaks the moment you update past 2026.9.0, which makes it feel like the update itself is broken rather than a config line that finally got flagged.
How Do You Confirm This Is Your Actual Cause?
Before editing anything, check your logs. SSH or Terminal add-on in, then open configuration.yaml and search for extra_module_url. If it’s there, that’s very likely your cause — you can stop guessing and go straight to the fix.
If you don’t have that line, check the Home Assistant log (Settings → System → Logs) for frontend errors mentioning a 404 on a .js file path under /local/ or /hacsfiles/. That points to the same family of issue: a resource reference the frontend can no longer resolve.
No matching line, no matching log error? Skip to the fourth section — your cause is probably a stale browser cache or a broken custom integration, not this bug.
Fix the Loading Error: Remove the Leftover Resource Line
Step 1: Open configuration.yaml. Use the File Editor add-on, the Studio Code Server add-on, or SSH — whichever you normally use to edit config files.
Step 2: Find and comment out the extra_module_url block. Put a # in front of the line (or the whole block if it spans several lines). Don’t delete it outright yet — commenting it out is reversible if something else was depending on it.
Step 3: Check configuration validity. Developer Tools → YAML → Check Configuration. Green means you’re clear to restart.
Step 4: Restart Home Assistant. Settings → System → Restart, not just a browser refresh. The frontend needs a full reload to drop the broken reference.
Step 5: Re-add card-mod through HACS if you use it. Newer HACS versions register the resource automatically, so you likely don’t need to add anything back manually — just confirm card-mod still shows up under Settings → Dashboards → Resources.
Most reports on the community forum say the dashboard comes back within seconds of the restart. Honestly, that’s usually enough — you don’t need to touch anything else.
What If Removing the Line Doesn’t Fix It?
A smaller share of reports needed a second step. Try these in order:
Clear the browser cache for your Home Assistant URL. The frontend caches JavaScript aggressively, and a half-cached bundle from before the update can keep showing the old error even after your config is clean.
Update HACS itself before touching card-mod again. When I compared the changelog notes for HACS’s own 2026.9-compatible release against the card-mod release notes, the fix for this exact interaction landed in HACS first — an outdated HACS version can reintroduce the same loading failure even with a clean configuration.yaml.
Check for other custom Lovelace resources added manually. Anything added through the old “Resources” UI path pointing at a file that a HACS update relocated will trigger the identical blank-screen behavior. Settings → Dashboards → Resources is where to look.
If none of that works, a full restore from your last pre-update backup gets you a working dashboard while you wait for the next patch release — most environments run backups automatically, so this isn’t usually a big loss.
Where This Error Actually Shows Up
Not every symptom means the same thing. Here’s what the confirmed extra_module_url cause looks like across the different places you might notice it:
| Where You See It | What It Looks Like | Confirmed Cause |
|---|---|---|
| Browser dashboard | “Could not load Home Assistant. Please refresh the page” banner | Leftover extra_module_url entry |
| Companion mobile app | Same message, or a blank white screen | Same — app renders the same frontend bundle |
| Settings → Integrations | Page fails to render or throws an error on load | Same broken resource reference blocks that page too |
| General interface, before it fully fails | Feels slow, icons missing | Frontend repeatedly trying and failing to fetch the deprecated file |
Before You Restart Again
- Back up configuration.yaml before editing it — a single misplaced comment character breaks YAML parsing entirely.
- Don’t skip the “Check Configuration” step. Restarting on invalid YAML can leave Home Assistant stuck at boot.
- If you use card-mod for a specific dashboard theme, screenshot it first — reconfirming resources after the fix is easier when you know what it should look like.
- Note your current version before downgrading anything. Some entity and automation formats in 2026.9 aren’t backward-compatible with 2026.8.
As of the September 2, 2026 release, Home Assistant’s own changelog documents the frontend resource-loading change as part of the 2026.9 core update (home-assistant.io). The GitHub issue thread opened the same week shows moderators confirming the extra_module_url removal as the working fix for the majority of reporters.
FAQ
Does this bug affect Home Assistant OS, Container, and Core installs the same way?
Yes. The failure lives in the frontend resource loading, not the install method, so Home Assistant OS, Supervised, Container, and Core installations all show the identical symptom if they carry the same leftover configuration line.
Will removing extra_module_url break my card-mod custom styling?
No. Current HACS versions register card-mod’s resource automatically, so your existing card-mod styling keeps working once the frontend can load again. You’re removing a now-redundant manual registration, not the card itself.
Is there a way to roll back to 2026.8 if the fix doesn’t work for me?
Yes, through a Supervisor or Home Assistant OS backup restore taken before you updated. Downgrading isn’t officially supported outside of a backup restore, and some automations saved under 2026.9 may not translate cleanly back to 2026.8.
Sources
- Home Assistant 2026.9 full changelog
- GitHub issue #181212 — “Could not load Home Assistant” after update
- Home Assistant Community forum thread
