Description of problem: Firefox doesn't play videos hosted on youtube within google+ interface. Version-Release number of selected component (if applicable): Firefox 41.0.2 How reproducible: Allways Steps to Reproduce: 1. An example, go to https://plus.google.com/109637860626261571611/posts/DnGCTXw5RRS?pid=6209230762541382930&oid=104349425299854550670 Actual results: Some screens from video are shown, the video stops. Trying to play shows "An error ocurred. Please try again later". This happens with all videos inside google+.
This works for me. Please try a fresh profile and in case if it is working please check if you have any of these settings changed: http://forum.pinguyos.com/Thread-Enable-Hardware-Acceleration-in-Firefox-Get-1080p-in-Youtube%E2%80%99s-HTML5-player
Also please test in safe mode ($firefox -safe-mode)
I tried both --safe-mode and a new profile, and the linked video above still doesn't play. Here's youtube player debug information: {"cpn":"g8eg6_w4-Aj4tiRA","vct":"0.000","vd":"NaN","vpl":"","vbu":"","vpa":true,"vsk":false,"ven":false,"vpr":1,"vrs":0,"vns":0,"vec":null,"vvol":0.97,"state":"80","debug_error":{"errorCode":"api.invalidparam","errorDetail":null,"message":"Ocorreu um erro. Tente novamente mais tarde.","messageKey":"YTP_ERROR_GENERIC_WITHOUT_LINK"},"debug_videoId":null,"cgr":true,"debug_playbackQuality":"unknown","debug_date":"Thu Oct 29 2015 16:51:02 GMT+0000 (WET)"}
Well, I can reproduce that. I can't also play that with upstream Mozilla binary.
Please make sure you have ffmpeg-libs installed. Firefox removed support of gstreamer and moved do ffmpeg.