Created attachment 8803995 [details] report.txt User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:51.0) Gecko/20100101 Firefox/51.0 Build ID: 20161024004016 Steps to reproduce: With 51.0(a2) version, I can't get audio on some videos, like this one : http://video.webmfiles.org/big-buck-bunny_trailer.webm I get only like 100ms when I seek part of the video, but it cut right after. Web player like youtube works (but it seems ads do not). What is weird is that it works with the 49 version (they are both installed). And it works when I use my headset (plugged in usb), but not with my sound card (Creative X-FI Titanium) I join my debug report. Actual results: No audio Expected results: I should have the audio of the video !
Can you please follow the instructions there: https://bugzilla.mozilla.org/show_bug.cgi?id=1309694#c24 and see if the version there fixes the problem for you. and if so, this is a dupe of bug 1309694
I feel really bad because I looked really **** lots of site (reddit, google, bugzilla), and still missed this bug report. This is definitelly a duplicate, first exe works, second doesn't. Sorry for wasting time. Keep up the great work !