Hello,

First, do you get sound from websites other than YouTube (e.g. try this video) in Firefox?

Sadly no luck. Thank you.

Ok, at least now we know that Firefox doesn't play any sounds at all, so it isn't a YouTube-origin issue.

You mentioned that you had tried solutions suggested in Firefox Support articles, but just to make sure: have you checked the Volume Mixer? In case you haven't, follow these steps:

1. Open Firefox and play any content that should play sound.
2. Right-click the volume icon in the Windows taskbar.
3. Click Open Volume Mixer. The Volume Mixer window will appear.
4. Make sure the slider for Mozilla Firefox is not muted or at the bottom.

Also, you mentioned that sound on your computer worked. To make it clear, did you mean it plays in Windows and other apps? If yes, here are some more things to try (just skip the ones you have already done):

• clear Firefox cache;
• allow audio autoplay for all websites in the Settings;
• run Firefox in Troubleshoot Mode.

Sorry if this is something you have already seen, but we need to make sure it does not help before proceeding.

Tried all things, sound mixer many times and Firefox was not muted. Good news, bad news, while fiddling around I did something and the sound worked on Facebook. I then checked YouTube and other sites and they are back. Do not know what I did, but thank you for your effort helping me.

Glad you got the sound back! In case it happens again, do not hesitate to ask a question.