I'm running 4.0.3 Build 16878, Win 8.1 Pro & Firefox ESR 52.1.2 - 32 bit. Clips play, but ..
I can't find overlays - which used to be an option when adding a camera. Now there's an Audio checkbox.
Setting Remote Access / Advanced .. Live and Clips to Original, with no overlays checked, is the only setting that works for me.
I removed shark, rebooted and the clips still played. Reinstalled shark = doesn't matter. Overlays are hosed on my box.