Sorry to hear about the crashes. Are you getting the Mozilla Crash Reporter dialog, or the Windows Ubuntu crash dialog? If you are getting the Mozilla Crash Reporter form, your Firefox may have logged some data that would help track down the cause of the problem. You can submit that data to Mozilla and share it with forum volunteers to see whether it points to the solution. Please check the last section of the support article "Firefox Crashes" for steps to get those crash IDs from the about:crashes page, and then post some of the recent ones here.

Note: pasting the IDs that start with bp- is easiest for forum volunteers since the forum automatically linkifies them.

I believe GStreamer is used to decode MPEG media in the native HTML5 video player, but only on Linux. As a Windows user, I'm not very familiar with the effect of disabling GStreamer but you could test it out here:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste media and pause while the list is filtered

(3) Double-click the media.gstreamer.enabled preference to switch it from true to false

Not sure whether that takes effect immediately, or only in new windows, or only after quitting/restarting Firefox.

The latest crash ID is in my original message. The Mozilla crash reporter is the one coming up. I'm hesitant to disable gstreamer, because I think it's integral to the functioning of so many sites now, but if there is no other option I'll give it a try.

That is a problem with the HTML5 media player and GStreamer support.

• Firefox 38.0 Crash Report [@ libgstreamer-1.0.so.0.405.0@0x8567c ]

Make sure that you have the latest GStreamer updates.

Otherwise you can try to disable GStreamer support by setting media.gstreamer.enabled to false on the about:config page.