When you play a video in AVPlayerViewController, the screen is completely dark.

Playing videos in AVPlayerViewController

We have created a controller class that inherited the AVPlayerViewController and are playing it back with the following code:

self.player=[AVPlayer playerWithURL:url];
[self.player play]

When I start playing, sometimes the screen becomes completely dark and no video is displayed.The audio is playing.
Continuous reproduction or difficulty in reproducing.

iOS version: 10.0.2

Please advise me on a workaround.