I'm trying to turn on the cameras in the Valve Index headset but the camera test says there's a communication error. All the options in the SteamVR indicate that it should be on and working. Device Manager shows a camera device and it does not look like it's missing drivers or has any issues. What else can I do?
Aside from turning it on inside SteamVR menus, you may have to enable access to your camera through Windows 10 system settings menu:
To find this setting page just type "camera" after opening the Start menu and you should get a link to it. Flip the toggle button to On in the "Allow apps to access your camera" section. This should be enough. Because SteamVR is not a Microsoft Store app, it doesn't look like it will be listed in a list of per-app permission toggles below. Flipping just the one switch on top helped me turn on the cameras.