HI, I understand that there is no sound in Netflix or HBO go when you watch vidoes or live streaming in Firefox. I am happy to help.

Since they use Silverlight, I might first recommend reinstalling the latest version of Silverlight.

Second there is a new feature where you can mute a tab, please see the icon in the tab to make sure that the sign for no sound is not checked. *What to do if Firefox won't play any sounds

Thanks for the reply. The tab is not muted and I removed and reinstalled Silverlight. I am thinking it must be a recent change in a plugin that Netflix and Amazon Prime use that HBOGO does not. Two Win 10 desktops still have sound on Netflix but the video Win 7 system just lost sound a couple days ago. I loaded dare I say it Chrome and the Netflix and Prime sound works. Tim

See also:

• https://blog.mozilla.org/blog/2015/12/17/firefox-users-can-now-watch-netflix-html5-video-on-windows/
• http://techblog.netflix.com/2015/12/html5-video-is-now-supported-in-firefox.html

I for years was a big fan of Firefox. I have gotten on help with the loss of audio on Netflix and Prime. I am sadly switching my browser to Chrome. Tim