I have six Dahua IPC-HSW4300C and two IPC-HFW1320 cameras on my system. All work great except for one small problem. For some reason, when I choose the "Overlay" tab within "Video", most of the settings are covered with a live video shot that is populated wih four small black squares in one corner. I can't remove the video to get to the settings. I am having the same problem with all eight cameras, so it must be something I am doing wrong. Perhaps someone out there can push me in the right direction.