The sound has disappeared on Firefox but works with other browsers. Can anyone tell me how to fix this?

Check to see if volume is not turned down on the video. Then check to see if windows volume is not turned down. Last click the little speaker icon, select mixer, if you have that option and check to see if Firefox is not muted.

If you have problems with current Shockwave Flash plugin versions then check this: * see if there are updates for your graphics drive drivers '''https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration''' * disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later) '''https://forums.adobe.com/message/4468493#TemporaryWorkaround''' * disable hardware acceleration in the Flash plugin '''https://forums.adobe.com/thread/891337''' See also: * '''http://kb.mozillazine.org/Flash#Troubleshooting'''