1965971 - "Media resource could not be decoded" Error in extensions

Status: RESOLVED DUPLICATE of bug 1727383

(WebExtensions :: General, defect)

Description

[Max Xie]

Attachment: test-extension.zip

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:138.0) Gecko/20100101 Firefox/138.0

Steps to reproduce:

1. Install the test extension
2. Click the extension action icon to open the test page
3. Open the browser console
4. Refresh the page repeatedly (it may trigger the issue on the first page load, but it may also take many refreshes)

Actual results:

Intermittently, some audio elements fail to load with the following errors in the console:

Media resource moz-extension://c2e41295-cd60-48cd-bee0-e62a562d3d43/audio/success.mp3 could not be decoded.Uncaught (in promise) DOMException: The media resource indicated by the src attribute or assigned media provider object was not suitable.
Media resource moz-extension://c2e41295-cd60-48cd-bee0-e62a562d3d43/audio/success.mp3 could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_METADATA_ERR (0x806e0006)

Expected results:

All audio elements should load and be able to play the audio file consistently.

Comment 1

[Alex Cornestean]

Hello,

I was unable to reproduce the issue on the latest Nightly (140.0a1/20250514211700), Beta (139.0b8/20250514034321) and Release (138.0.3/20250512124033) under Windows 11 and Ubuntu 24.04 LTS.

As per the steps to reproduce, I refreshed the test page a few hundred times and the errors did not show up in the browser console. I’ll keep trying and post any updates.

Comment 2

[Max Xie]

Hi, I have a new discovery after some more testing. It seems the way the extension is loaded has an impact on the behavior.
If I load test-extension.zip directly, I can't reproduce the bug.
If I unzip test-extension.zip and load the extension via manifest.json, I can reproduce the bug.
In my testing, the above behavior is consistent in both Firefox Release 138.0.1 and Nightly 140.0a1 (2025-05-14) on Linux.

Are you loading the extension zip directly? If yes, can you unzip it and try again?

Comment 3

[Alex Cornestean]

Hello and thank you for the additional info !

I reproduced the issue by loading the manifest.json file directly, on the latest Release (138.0.3/20250512124033), Beta (139.0b8/20250514034321) and Nightly (140.0a1/20250515230342) under Windows 11 and Ubuntu 24.04 LTS.

As soon as the test page loads, the console logs the mentioned errors. Several refreshes later, the errors are logged again.

Comment 4

[Rob Wu [:robwu]]

I have seen this exact error before, in bug 1727383. In the other bug, it was happening in a background page, but in this bug it looks like the issue happens generally in a moz-extension:-document.