Hi Tim – I did some tests at my end and it’s working with my Microsoft webcam and OpenBroadcaster’s VirtualCam plugin. This is probably unlikely but just to rule it out, is there any chance that your privacy settings are preventing FF from accessing the camera? If you use the Windows search function to find “Camera Privacy Settings” are the relevant permissions toggled on (“Allow desktop apps to access your camera” etc). If I toggle that to off I see the same thing – the device is listed but the start button has no effect. As I said, just to rule it out as a possible cause.