Videos won`t play on Firefox browser

Report · Nov 12, 2016

Videos will play on Microsoft Edge but not on Firefox on the same computer. The computer is Windows 10 and Firefox 49.0.2. The videos i`m trying to play are on a news site named "nine.com.au". I have the latest Adobe, FlashBlock, and Ublock installed. When i open each video to play, the black "f" in a circle with a white background appears. Also, the error Adobe has crashed will eventually appear. I`ve tried many things with Mozilla, who referred me to you e.g. disabling FlashBlock and Ublock, disabling hardware acceleration and tried going through safe mode but no change with any of those. Could you help please.

Report · Nov 13, 2016

Hello. I visited nine.com.au using Firefox 49.0.2 with uBlock Origin and the latest Flash Player NPAPI (23.0.0.207) and was able to play all videos (however two were silent for some reason), perhaps because I'm not running Windows 10, but more likely because I'm not using FlashBlock (which is obviously not an Adobe product).

Report · Nov 13, 2016

Thank You for your reply. As you see in my attachment there is Shockwave Flash. At the bottom there is "Enable Adobe Flash protected Mode". If i tick it on this computer the videos won`t play on Firefox. If i untick it the videos will play on Firefox on this computer. My other computer has always had it ticked and videos will play anytime. Both computers are the same Internet Provider and Windows 10 with Firefox 49.0.2. Mozilla Firefox has told me that to untick that would make my computer unsafe. So, what does Adobe think. Also, is Flashblock necessary.

Report · Nov 14, 2016

One of the things that Flash Player does when it's running in Protected Mode, is validate that it's actually talking directly to Firefox. There are a number of video capture tools that try to save Flash video to disk (RealPlayer did or used to do this), and would effectively shim themselves between Flash Player and Firefox. This was also a good technique for malware authors, which is why we make sure that there are no intermediaries in the conversation between Flash and Firefox with protected mode enabled.

That's really about the only thing that I can think of that would cause video not to play with Protected Mode enabled. My guess is that you've installed something like a video downloader or some security snake oil that's inserting itself between the browser and plugin. Depending on what it is, it may have to be completely uninstalled to get things back to normal. If it's another plugin, you could try enabling Flash Player's protected mode and going to Firefox > Help > Restart with Add-Ons disabled. If everything works, then you'll need to disable all of the other add-ons, and then re-enable them one by one until you find the culprit.

Alternatively, the 64-bit variant of Firefox offers a native NPAPI sandbox, which is much better than Flash Player's protected mode. The Flash Player sandbox for 32-bit Firefox was a necessary response to a changing security landscape, but something we had to bolt on to the wrong side of the plugin interface, because at the time, Mozilla was not interested in building a sandbox for plug-ins. It's several years later now, and Mozilla has made that investment for 64-bit Firefox on Windows already, and we're hopeful that a native NPAPI sandbox for 32-bit Firefox will be available in the future, allowing us to retire Flash Player's protected mode.

Report · Nov 14, 2016

Thank You. With Flash Player's protected mode enabled and going to Firefox > Help > Restart with Add-Ons disabled After that i restarted Firefox, no change. The NPAPI sandbox looks interesting. Should i install it and if so could you show me where to install it from please??

Report · Nov 14, 2016

You can grab it here:

Mozilla Firefox Web Browser — Download Firefox in your language — Mozilla

Report · Nov 14, 2016

Thanks, i thought it was just an add on. Is it a new Firefox browser?

Report · Nov 15, 2016

There are 32-bit and 64-bit variants of Firefox. The 64-bit variant is newer, but it's been around for a couple years. It includes a native NPAPI sandbox, which obviates the need for Flash Player's protected mode. If this is really an issue with Protected Mode (or more likely, some third-party application -- legitimate or otherwise -- conflicting with protected mode), the native NPAPI sandbox may be more forgiving. It's also offers equivalent security protections, but it's inherently more efficient.