No video from capture device when running from command

[uxvideo]

Hi!

I am trying to display video from a capture device (such as USB microscope or webcam) on my computer screen.

When I start it from the GUI it works. Though it opens in a new window even when I checked "allow only one instance" in the options.
When copy the "Edit Options" and the "MRL"(("dshow://") ) from the open media dialog box (under "show more options") to a .vlc file and run it I only get an empty player where the time is ticking, but no video.
I haven't found anything in the forum about this. Does anyone have an idea about what could be the problem?