Hi

That error does look like an issue at the YouTube end, but please appreciate that you are using an older version of Android that is increasing longer supported by a growing number of apps.

I have this problem too. Hopefully I'll be able to give you more info, which suggests it's not YT issue.

I have an old LG G4 phone with Android 6.0, which I'm using as music player and to look some youtube videos occasionally.

So, one moment YT videos work, the next I update the app to 143.0 (which boasts "xHE-AAC support: Play higher quality audio on devices running Android 9 and above" in what's new section and will be relevant later). And just like that, after the update the videos stop playing. It's all a coincidence, right? Wrong. It seems so, but facts appear to show a different story.

The facts are: - FF stops playing YT videos as soon as it gets updated - another browser on my Android 6 device plays the same videos just fine - FF on my Android 14 device plays the same videos just fine - YT debug logs always show one particular error thrown: "debug_error": "{\"errorCode\":\"fmt.decode\",\"errorMessage\":\"Wystąpił błąd. Spróbuj ponownie później.\",\"Bm\":\"GENERIC_WITHOUT_LINK\",\"sL\":\"vct.0.000;vd.942.641;vpl.;vbu.0.000-5.500;vbs.0.000-942.641;vpa.0;vsk.0;ven.0;vpr.1;vrs.1;vns.1;vec.3;vemsg.Error no decoder found for audio/opus;vvol.1;vdom.1;vsrc.1;vw.360;vh.203;mediaElem.1;trg.melem\",\"TE\":1,\"cpn\":\"XETC_H4ClJ2q25Fg\"}", Look no decoder found for audio/opus - audio related issue just as FF made some audio related changes. What a coincidence! - FF on android 6 can't play any YT video, sorts, completed transmission, but it can still play live transmissions (probably due to YT using different codecs for live transmissions) - I asked my friend with Android 6 device to repeat my testing on freshly installed FF and they came up with identical results

Please, test it out yourselves and fix it. And yes, I understand that supporting old OSes means more work but on the other hand, I really don't want to throw away a device which still works perfectly fine for the things I'm using it for.

The latest update fixed the problem. Thanks! 👍