In a fresh profile youtube works fine in recent nightly builds for me, but in two existing profiles with lots of windows etc, youtube won't play. I've seen this in builds from over the past couple of weeks I think. Embedded youtube instances do play, but if I go to, say, https://www.youtube.com/watch?v=jW8ICe0YPgA then see the first frame with the youtube spinner over it, but no playback of video or audio. Here's about:media when that happens: HTMLMediaElement debug data https://www.youtube.com/watch?v=jW8ICe0YPgA blob:https://www.youtube.com/d923dcec-d549-47f5-a53d-dde9a3eeb3b2 currentTime: 0 readyState: 4 Quality: -- (total:0 dropped:0 corrupted:0) Buffered ranges: [(0, 150.001)] SourceBuffer 0 start=0 end=150.001 SourceBuffer 1 start=0 end=155.001 Internal Data: audio decoder: shutdown audio frames decoded: 1 audio state: ni=0 no=0 ie=0 demuxr:0 demuxq:0 tt:-1.000000 tths:-1 in:0 out:0 qs=0 pending:0 waiting:0 wfk:0 sid:3 video decoder: shutdown hardware video decoding: disabled video frames decoded: 1 (skipped:0) video state: ni=0 no=0 ie=0 demuxr:0 demuxq:0 tt:-1.000000 tths:-1 in:0 out:0 qs=0 pending:0 waiting:0 wfk:0, sid:2 Dumping data for demuxer 7f04dc097800: Dumping Audio Track Buffer(audio/opus): - mLastAudioTime: 0.000000 NumSamples:7500 Size:4719363 Evictable:0 NextGetSampleIndex:0 NextInsertionIndex:7500 Buffered: ranges=[(0.000000, 150.001000)] Dumping Video Track Buffer(video/webm; codecs=vp9) - mLastVideoTime: 0.000000 NumSamples:4650 Size:12906024 Evictable:0 NextGetSampleIndex:0 NextInsertionIndex:4650 Buffered: ranges=[(0.000000, 155.001000)]
Can you please copy the output of about:support on one of the profile that doesn't work. To see which prefs you've changed.
sounds like the disable auto-play setting is set, that messes up with youtube.
Aha! That was indeed it. Is that a youtube bug or our autoplay stuff? Thanks! Guessing we should mark this invalid unless there's work to do for autoplay disabling...