Possibly, this happens when you are trying to play the mp4 file with Windows Media Player or Quicktime which do not support the mp4 codec on your computer. 

Please convert the mp4 file using our image converter first. This will convert the mp4 file to AVI format(Windows version) or MOV format(Mac version). Converted AVI or MOV file should be playing fine with WMP or Quicktime. 

Following is the link where you can download the converter:

http://www.rolandsystemsgroup.com/products/100085#tabDownloads

However, if you wish to just play the file on your computer, please use VLC player instead of Windows Media Player or Quicktime. VLC player plays the mp4 file without conversion. 

Thanks!