Greetings. I have tried to fix this problem with H264, and nothing works. I have FF 47.0.2 with Shockwave flash 18.0 r0, running under WinXP SP2. Couple of years ago H264 files stopped playing in the FF (with «unsupported MIME type» error), but I can always download the file and play it locally. Youtube played everything well, although switching to HTML5 player made it slower. YT's HTML5 test page showed, that I was able to play everything, except "H.264" and "MSE & H.264".
Things got worse 2 months ago, when I noticed that live streaming on YT is not working anymore. Then, new videos are not necessary playing. And now, some older videos are also not playable (but they were in the days of a flash player). Can I switch back to flash player on YT? They seem to quit supporting it altogether, even for embedded codes (it worked for some time).
Now, I followed every step in this manual, adding all those config lines and installing Primetime CDM 17 properly (so it's visible and «always active»). HTML5 page is now showing all 6 blue ticks, even for 264, but 264 videos are not playing, there is just an everwaiting spinner. Live streams upon loading are showing a small "JavaScript Application" window with "Error: videoFormats is null" message and OK button. Video stats showing that "mp4a" format is problematic, as VP9, Opus and OGG-Theora are playable as before. MP4 videos from other sources are not playable in FF as well.
Is there anything else I can do? Maybe, some debug info would help, if only I knew where to look.
