I figured out the mute/solo buttons but when I add a video to my project there is no sound. Is this a bug? I can't find any information on this subject. I just spent $50 so I can make a family member a wedding video and so far I'm irritated beyond belief.
Go to 'Render as' and select a default template in the format you desire, select 'Customize Template' and confirm the 'Include audio' box is check-marked.