FCPX 10.3 When Playing Video Some Photo Clips Display as Black Screen - Happens Randomly

I am running Mac Sierra OS and recently upgraded to 10.3. When I play my video some of the clips (which are photos) display as black screen. The audio is working fine. This happens randomly. When I go back to the timeline and move back and forth through my project, doing some editing, and then come back to play the video, the clips that previously displayed as black now display and other clips go black. Any thoughts would be appreciated. Thank you.