Last three versions of my project.
Audio from video
Audio will work from the previous versions of my projects.
The files are MOV files and are tagged as Quick Time Movies.

I have been using my this movie studio version 13 for a two weeks now and have not had this problem before.

I am tempted to uninstall and install again.

Post a screenshot of your timeline.
Reinstalling the program won't fix a thing in your project.

Thank you. Your request prompted me to explore my time line and I found out it was simply the mute button. I thought I had tried this before ....... .

Don

Good to read it's fixed, . . . . . but this kind of issue demonstrates a flaw in the software - that with so many Options you can get into a State which you don't remember.
It would be sensible for Sony to set up a "Restore Point" -( provided that is you have been working OK ).
Ideally it would be a flashing screen effect, so all the differences are showing - that way you can check them out one by one without losing the "good ones" .
The mute features are rather too small and poorly illuminated. again it's down to the programmer - in the days of CRT-Monitors it was bad-practice to have stationary high-brightness regions ( Screen-Burn), but that was some years ago.
There is a screen-layout restore feature for when you lose one of those panels and I usually put the Audio Meters to the Left of the Preview, since when you Render, the "Progress Panel" plonks itself in the middle so you cannot watch all the preview . . . .it's nice to know that every event is present.
Making info-Panels unmovable is sloppy programming...IMHO.

I'd also like to see more advanced locking of screen layouts and features. It would be nice after getting the screen arranged just the way i like it to be able to disable dragging/resizing screen elements! Honestly, other than by accident, i have not rearranged my Vegas screen in the last 15 years, other than to set up each new version install once. But when i do move things by accident i lose track of where things are or sometimes can't even see them anymore.

If we were never going to use mute or pan or phase invert, or other such easily clickable not not instantly noticeable features, it would be nice to say "i'm never gonna use this, so freeze & disable it."

Of course, all of these would be undoable and redoable in the "feature lock" screen.

Both these suggestions are excellent and would be very welcome.

Back to my audio problem. I was just about to report my lack of progress so here it is.

My audio worked until my latest project which refuses to play the audio when editing or playing back. Internet radio works, the volume control is not muted. My conclusion is that I have prodded an option in Movie Studio which has switched it off. I have searched around and there is nothing obvious. musicvid offered to help me if I sent a screenshot of my timeline. I declined to do this as I thought I had solved the problem but it has reverted to its faulty state.
I am not sure how to send the screen shot so I will send you this first and then the screen shot