If you try to load a video in VideoPlayer, but the source does not exist. And then try to load another video.
The previous loading is stuck in intermediate state, and when try to load new source, theres a null pointer exception in VideoDisplay in function cleanUpSource() at lines: videoPlayer.displayObject.visible = true; because videoPlayer.displayObject is null. The previous aborted loading has not initialised it yet.
add " if(videoPlayer.displayObject) " before the two lines videoPlayer.displayObject.visible = true; of this function cleanUpSource()
In fact everywhere else in this Class theres always this if when this variable is used. So its logical to do it here also.