What caused the error?
The error happened when I tried to display view from my web camera in a VideoDisply object but insted I got black screen. I was sure that camera was connected and it was working with other applications (e.g. Skype).

What is the solution?
Right click on any Flash content and choose “Settings”, then go to the “Camera” tab (section) and check if your camera is listed there. It should. In my case there were two additional cameras “Google Camera Adapter” and one of them was selected. They probably came with Google Talk plugin.

As soon as I selected “Creative WebCam” everything started to work.