There's an app for Mac (among others) called Open Broadcast Studio (OBS) for livestreaming and other direct video work. One of its features is a virtual video camera that is an optional OBS installation. Once done, Parallels complains on start of any virtual machine: 'Unable to connect "Virtual Video Camera" to [virtual machine name] now. Try to connect this USB device later.' It's not a USB device, although it might appear to be. OBS need no longer be running, it happens all the time after this sub-installation. I'm not concerned about being able to use this virtual camera in Parallels, but it would be nice to gracefully ignore it. It's used to connect things like Zoom where you have to pick a camera and you want to show your OBS session. Might be nice to use in a VM if possible.