-(IBAction)play:(id)sender { thumbImageView.alpha=0.0; NSString *stringvideo=[NSString stringWithFormat:@\"http://streaming-service\",[[NSUserDefaults standard
Not a direct answer to the question, but if you get this error after trying to update contentURL, calling stop() before solves the problem.
moviePlayerController.stop() moviePlayerController.movieSourceType = .File moviePlayerController.contentURL = newURL