Media Panel shows no images
I have created a Media Panel interaction in Engage 13. I have added mp3 and mp4 files that come from a variety of sources, including YouTube, our corporate video recording studio, and PowerPoint wmv files. All import and play correctly. However, they all display a black or white box instead of an image from the video.
Is it possible to display an image or add a caption to identify the media that will be played when the "graphic" for that media is selected?