Did you try updating your graphics driver or disabling hardware acceleration (about:preferences#advanced)? I had an issue but on Windows 10 where sometimes on

Did you try updating your graphics driver or disabling hardware acceleration (about:preferences#advanced)? I had an issue but on Windows 10 where sometimes on video playback FF would just lock up and windows would restart the graphics driver. I also couldn't reliably reproduce it, it sounds like a similar problem. This is my bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1280706 https://bugzilla.mozilla.org/show_bug.cgi?id=1280706