HOME ASSISTANT 2026.9

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 cases below look similar after an update but have a different status. This guide was first published on 5 September 2026, and the status of the reports was updated on 1 October 2026.

CURRENT STATUS

What has changed since 2026.9.0?

Since the first version of this guide was published, Home Assistant has released 2026.9.1, 2026.9.2, 2026.9.3 and 2026.9.4. Some issues from 2026.9.0 have already been fixed, but similar symptoms do not always have the same cause.

If Home Assistant no longer loads the interface, starts restarting or becomes unresponsive after an update, first check the exact Core version and the specific symptom. This helps separate the fixed device registry issue from reports that are still open.

IDENTIFY THE PROBLEM

First identify the symptom you are seeing

The most commonly reported 2026.9 problems can look similar at first:

the interface shows “Could not load Home Assistant” in the browser or companion app;
Home Assistant starts, RAM usage rises sharply and Core enters a restart loop;
Core becomes unresponsive while Supervisor remains available and memory usage stays normal;
Home Assistant itself works, but a specific integration, HACS card or part of the interface stops working.

These should not be treated as one failure. Different symptoms require different diagnostics.

ISSUE 1

"Could not load Home Assistant" after the update

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.

One confirmed cause reported by users was an old extra_module_url entry in configuration.yaml pointing to the HACS card-mod.js file. On installations where that entry was still present, removing or commenting it out and restarting Home Assistant resolved the problem.

However, this does not mean every “Could not load Home Assistant” error after 2026.9 has the same cause. The main issue report for this symptom remains open, so it is worth checking the logs, the exact Core version and whether the problem is also present without custom frontend elements before making further changes.

ISSUE 2 · FIXED IN 2026.9.1

Restart loop and a sharp rise in RAM usage

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.

A confirmed 2026.9.0 issue could cause device_registry to grow or behave in a way that resulted in very high memory usage followed by Core restarts. Issue #181120 was closed after fixes were introduced.

Home Assistant 2026.9.1 included changes that purge unreachable deleted devices when the device registry loads and speed up lookup of colliding orphan entries in device_registry.

If you are still running 2026.9.0 and this is the symptom you see, check your backup first and consider updating to the latest 2026.9 patch before doing deeper diagnostics. If the same type of failure occurs on a later version, do not assume automatically that the cause is identical.

ISSUE 3 · SEPARATE REPORT

Core becomes unresponsive without high RAM usage

There is also a separate report where Home Assistant Core becomes unresponsive without an OOM event or a sharp increase in memory usage. Supervisor remains available, detects missed Core API responses and eventually restarts Core through the watchdog.

This case was deliberately separated from the device_registry problem because the memory symptoms are not present. Issue #181318 does not yet identify one confirmed cause, so fixes intended for Issue 2 should not be applied to it automatically.

DIAGNOSTICS

What to check before rolling back

Before restoring an older version or backup, note a few things:

the exact Home Assistant Core version;
whether the problem occurs in both the browser and companion app;
whether Supervisor remains available;
whether RAM usage rises before Core restarts;
the most relevant Core errors and warnings;
whether you use HACS, custom cards or custom integrations;
the date of your last known good backup.

If the problem appeared immediately after an update, avoid making several changes at once. Do not delete the database, .storage files or integrations blindly just because they appear in the logs. First determine whether the failure is in Core, a specific integration or the frontend layer.

The general, safe troubleshooting order for any update is covered in the Home Assistant not working after an update guide.

BEFORE YOU UPDATE

2026.9 breaking changes worth checking first

If you are still on 2026.9.0 or an earlier patch, check the full changelog first. Home Assistant 2026.9.4 was released on 27 September and includes the fixes from the earlier 2026.9.x releases. Updating will not, however, fix an issue caused by a custom integration, a HACS card or your own configuration.

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.

HELP

Is Home Assistant still not working correctly after the update?

If Home Assistant no longer loads the interface, keeps restarting, uses an unusual amount of memory or becomes unresponsive after an update, I can review the logs and configuration, determine whether the problem comes from the 2026.9 release itself, a specific integration or the configuration of your installation, and choose a safe fix before you decide to roll back or restore a backup.

→ Get in touch

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