Timeline no audio on inserted mp4

[Gray Susan]

A post at work from another developer had the following problem:

My Timeline don't have audio on inserted mp4. Mp4 works fine in any media player.

frustrating to place bookmarks without audio. the right driver in my computer works fine.

is there a setting in CP 2019?

In preview mode, the video is blackout. Any ideas.

I suggested him previewing in HTML5 Browser.  Now this is the problem he's having.

Loading a new project blank now has the HTML5 previewer. I also have audio when editing the video directly, which pops a window with a timeline of breakpoints.

However, double clicking on the slide timeline will not run the video or audio. timeline cursor runs normal.

I exit and reload CP 2019, then click on timeline. it follows with a window pop up saying loading video but stops at 50%. If cancel then I can proceed as above but no slide timeline video.

we are getting closer. any ideas?

[Lilybiri]

Perhaps audio is muted on the Timeline panel? 

However from the other descriptions, maybe try to re-encode the mp4 file using the Adobe Media Encoder packaged with Captivate.

I don't know what you meant about the breakpoints. Maybe a terminology problem.

The normal workflow in all Adobe applications to play something in the Timeline panel is to use the space bar if that panel is in focus, or else the control buttons in the panel. I never have seen a double-click for that purpose.

[RodWard]

From the text of the message it looks like this developer is more familiar with some other kind of software tool (perhaps related to video editing) and is assuming Captivate should work the same way.  Doubleclicking the Captivate timeline does not run video or audio.  It would more likely collapse the timeline layers view.

Has the developer undertaken any training in Captivate?  It looks like the project may involve 360 video, which can be quite complex.