cannot play the video from an MP4 file which worked well very recently

Hello to y'all,

I need some help.  An MP4 file was sent to me that was important. I watched and listened a few times but yesterday the video did not open properly and only the audio worked.  Instead I got an aqua colored screen and no video. Instead of any time line under the video I just got a red line moving quickly across the screen and I had no control whatever. 

Can someone help me correct this situation?

Thank you,

Photodoc16