Firefox doesn't come with his feature built-in, so you must have an extension that provides this feature and this extension isn't working for some reason. *https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Separate Issue; Your System Details shows; Installed Plug-ins Shockwave Flash 25.0 r0 Shockwave Flash 21.0 r0 <br>Having more than one version of a program may cause issues. You must remove the older programs. Then get the current full installer. Flash: Grab the uninstaller from here: http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html Uninstall Flash Player | Windows http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html Uninstall Flash Player | Mac Then reinstall the latest version. '''Note: Windows users''' should download the '''active_x''' for ''Internet Explorer.'' '''and''' the '''plugin''' for ''Plugin-based browsers'' (like Firefox). '''Note: Windows 8 and Windows 10''' have built-in flash players and Adobe will cause a conflict. Install the '''plugin only.''' Not the '''active_x.''' Flash Player '''Version: 25.0.0.171''' https://get.adobe.com/flashplayer/ Direct link scans current system and browser '''Note: Other software''' is offered in the download. <Windows Only> https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) '''Note: Other software''' is offered in the download. <Windows Only> ------------- See if there are updates for your graphics drivers https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration