YAML editor lost syntax highlighting and autocompletion since 2025.10.2 update

[alan-altruy]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

Since updating to Home Assistant Core 2025.10.2, the integrated YAML editor (used in Automations, Scripts, and Scenes) has lost both syntax highlighting and autocompletion.

The text now appears as plain text without any color, and no suggestions are shown when editing YAML keys or values.

This happens consistently on both desktop browsers and the Android mobile app.

Describe the behavior you expected

The YAML editor should display syntax highlighting and provide autocompletion for available keys, entities, services, etc., as it did before the 2025.10.2 update.

Steps to reproduce the issue

1. Update Home Assistant Core to 2025.10.2
2. Open an automation or script
3. Switch to Edit in YAML mode
4. Observe that syntax highlighting and autocompletion are missing

What version of Home Assistant Core has the issue?

2025.10.2

What was the last working version of Home Assistant Core?

2025.10.1

In which browser are you experiencing the issue?

Google Chrome 128.0.6522.195 (Desktop and Android) Also reproducible in Firefox and the official Home Assistant Android app.

Which operating system are you using to run this browser?

Android 16 (Samsung S23 Ultra) Windows 11 (Desktop)

State of relevant entities

Problem-relevant frontend configuration

None. Occurs with default dashboard and without custom themes or frontend modifications.

JavaScript errors shown in your browser console/inspector

No relevant errors.

Additional information

[alan-altruy]

[jeremysherriff]

Confirmed on desktop with Chrome 141, and Android Companion App 2025.8.7-full.

[LoveyDov3]

Same issue happening for me as well. Happy to hear I am not going completely crazy just yet! 🫠 lol

[gate546]

like many of us, same story here

too

[silamon]

It still works on the latest development, worked on 2025.10.1 and broke only on 2025.10.2.

[piitaya]

Looks like this yarn change went into the patch release d94fa03
But it should not. Maybe because of a merge conflict... not really sure why the bump has been included in the patch release.

I'm not even sure it's caused by this.

[sksarda-eng]

Seeing the same issue. Hoping that there is a patch soon.

[silamon]

Probably next friday, if it bothers you, suggest downgrading to 2025.10.1.

[JGNi]

I can add that if I maximise in YAML mode in automation editing, I can't minimise the window again.

[TTLucian]

Also the find / replace functionality is gone.

[GregoryPyck]

same issue, and also find/replace doesn't work anymore..

[jayjojayson]

Only for reporting, have the same issue and also the Function control+F is gone.