HD Movie Maker Pro

I need help asap!  I have created a movie for my grandfather who is dying and when I go to create the output video, I get the following message:  Failed to create the output video. Please try again!  (Access is denied: (Excep_FromHResult0x80070005).    The video is just under 16 minutes.  I did upgrade and buy the HD Pro, so it is not the free app.  I am doing this on a desktop computer as well.  

Thanks!