[Teea]

If you have the key board controller try f8

[Gillespiea]

If you have the key board controller try f8

Press the yellow button on the Android Remote. In some versions if Kodi that will turn mute off.

[BS1080]

Anyone coming back to this old post, might want to look at the Wiki...

http://kodi.wiki/view/Keyboard_controls

Which clearly shows that on a Keyboard, if you hit the Plus + or Minus - keys, that controls the volume in Kodi.

But unfortunately that did not work. I wasn’t watching TV for a long time. But I noticed that red icon too & I just couldn’t turn this muting off. Not with my Mac remote widget, not with the quich sidebar control & nor with a iOS remote. Just shortly before I gave up, I just tried the browser UI wich immediately worked out the way I wanted it to be. Just go on your local address of your kodi and use the volume up button there...