sidebar-card is trying to call setConfig() on a Lovelace element that no longer exposes it in newer HA frontend builds

[murf1]

Version Info:
Home Assistant OS
Core 2026.1.1
Supervisor 2026.01.0
Operating System 16.3
Frontend 20260107.1
HACS Sidebar card 0.1.9.9
HACS WallPanel 4.60.1

AI Analysis

1. TypeError: a.setConfig is not a function
   This means:
2. sidebar-card is trying to call setConfig() on a Lovelace element
3. That element no longer exposes setConfig() in newer HA frontend builds
4. Home Assistant recently changed how cards are instantiated internally
   That’s why you see it across:

• Electron (WallPanel / kiosk devices)
• Chrome (Windows)
• WebKit (iOS)

2. Cannot read properties of null (reading 'shadowRoot')
   This is the cascade failure:
3. sidebar-card fails to initialise
4. It tries to manipulate DOM elements that no longer exist
5. wallpanel hooks into the same DOM lifecycle
6. Boom 💥 — null shadowRoot

So wallpanel is not the root cause, it just exposes the bug more reliably.

Confirmed root cause (according to AI)
sidebar-card is currently incompatible with recent Home Assistant frontend versions
This is not browser-specific and not OS-specific.

Error Message:

Logger: frontend.js.modern.202601071
Source: components/system_log/init.py:331
First occurred: 05:18:14 (48 occurrences)
Last logged: 10:32:16

Uncaught error from WebKit 605.1.15 on iOS 18.7 TypeError: a.setConfig is not a function. (In 'a.setConfig(e)', 'a.setConfig' is undefined) /hacsfiles/sidebar-card/sidebar-card.js:462:2554
Uncaught error from Chrome 143.0.0.0 on Windows 10 TypeError: a.setConfig is not a function /hacsfiles/sidebar-card/sidebar-card.js:462:2545
Uncaught error from Chrome 143.0.0.0 on Windows 10 TypeError: Cannot read properties of null (reading 'shadowRoot') He (/hacsfiles/sidebar-card/sidebar-card.js:412:6836) /hacsfiles/sidebar-card/sidebar-card.js:412:10404 yp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:145123) Ep (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:220616) Sp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:221557) Cp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:222121)
Uncaught error from Chrome 143.0.0.0 on Windows 10 TypeError: Cannot read properties of null (reading 'shadowRoot') He (/hacsfiles/sidebar-card/sidebar-card.js:412:6836) /hacsfiles/sidebar-card/sidebar-card.js:412:10404 yp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:145123) Ep (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:220616) Sp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:221557) /hacsfiles/lovelace-wallpanel/wallpanel.js:3:224234
Uncaught error from Chrome 143.0.0.0 on Windows 10 TypeError: Cannot read properties of null (reading 'shadowRoot') He (/hacsfiles/sidebar-card/sidebar-card.js:412:6836) /hacsfiles/sidebar-card/sidebar-card.js:412:10404 yp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:145123) Ep (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:220616) Sp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:221563) kp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:223258) Cp (/hacsfiles/lovelace-wallpanel/wallpanel.js:3:222113)

[LordeXf]

First of all, many thanks to the devs for this repo.

Probably same here:

Version info:
Installation method: Home Assistant OS
Core: 2026.1.2
Supervisor: 2026.01.1
Operating System: 16.3
Frontend: 20260107.2
Sidebar: 0.1.9.9

Since a while, I'm facing some errors like this:

Logger: frontend.js.modern.202601072
Source: components/system_log/__init__.py:331
First occurred: 16:22:03 (12 occurrences)
Last logged: 16:30:19

Uncaught error from Edge 144.0.0.0 on Windows 10 TypeError: Cannot read properties of null (reading 'shadowRoot') He (/hacsfiles/sidebar-card/sidebar-card.js:412:6836) /hacsfiles/sidebar-card/sidebar-card.js:412:10404

It can sometimes produces hundred of errors in 1 minute