Mac: QtMultimediaPlayer example plays only sound and crashes

Player plays only the sound and crashes when playing with the options.

Steps to reproduce:
1 - Open a video

problem => the open file dialog doesn't popup

2 - resize the window and click open again, the dialog opens
3 - click play button

problem => only the sound works

4 - play with options available in the example

problem => the application crashes (see trace attached)