Video not playing during timeline preview?

I am having the same issue, but opposite. I created an .mp4 in Camtasia and imported it into a blank slide. It previews fine in the timeline, but does not play in slide or scene preview.

Update. I had sent the mp4 out for review in an email. I went to that email and dragged the file to my desktop and re-imported that one. Worked fine. Thoughts?