Affected versions

• Firefox 102.0b3
• Firefox 103.0a1

Affected platforms

• Windows 8.1

Steps to reproduce

1. Launch Firefox and access Facebook
2. Login with a valid account and select "Watch" category

Expected result

• Videos load and play as expected

Actual result

• An error is shown "Sorry, we're having trouble playing this video"

Regression range

• Will see for a regression.

Additional notes

• The issue can be seen in the attachment
• macOS and Ubuntu doesn't seem to be affected
• Windows 10 not affected, and Windows 11 (intermittent, seems related to scrolling while the page loads)

Does that Windows 8 you tested install the Windows Media Foundation yet? See here to see if helps.

I suppose you would see this kind of error message when you open the web console?

Cannot play media. No decoders for requested formats: video/mp4; codecs="avc1.4D401E".....

Hey Alastor. Windows 8.1 is fully updated, and other websites (ex. Youtube) works as expected. No message is shown in browser console when trying to see a video on Facebook.

Are you using Windows N/KN/Pro N? Because those Windows version don't come with the media package, even if they're fully updated. You have to install extra media package in order to play h264/aac.

Is this video working for you? Also, would you mind to help me capture debug log by using MOZ_LOG=timestamp,MediaDecoder:5,PlatformDecoderModule:5 while reproducing the FB issue?

Thank you.

Sure thing Alastor. Windows is only 8.1 Pro without any of the variations. The video you provided doesn't work on Firefox (works on chrome though), and it just says "Your browser can't play this video".

Used the MOZ_LOG=timestamp,MediaDecoder:5,PlatformDecoderModule:5 for Current log modules and the log files resulted are added in the attachment.

Could you try today's Nightly to see if the issue still exists or not? I think it was fixed by bug 1772053 already. Thanks.

Yep, seems to be fixed by bug 1772053. Will close this as wfm. Thank you!