Whenever I bring a video to fullscreen on YouTube (on Chrome or Safari), the video will go to fullscreen but the dock and menu bar remain visible, covering the top and bottom parts of the video. They used to be hidden when I went to fullscreen, so I don't know what happened. How do I fix this?
I have this same problem with YouTube, Netflix, mPlayerX and VLC, where the Dock stays visible (on-top) after making the video go full screen.
This problem can be fixed by going into System Preferences...Mission Control and turning off the option "Displays have separate spaces." You have to logout after making this change.