1) videoscribe failed to render the full video file or the file is corrupt.
2) recently installed software changed your video or audio codec(s)
3) you or your operating system attempted to open the file with the wrong video player or program.
You could put your .mov file on dropbox and share a link, if you want anyone else to examine it.
You could try making a new project with just one image and render a .mov file to see if it works.
-Mike (videoscribe user)
It might also be a good idea to raise a support ticket to discuss this problem with customer support.