Troubleshooting
Windows says "Windows protected your PC"
The downloads are not code-signed yet, so SmartScreen does not recognise the publisher. Choose More info → Run anyway. See the code signing policy.
"Camera in use"
Another application holds the camera and the driver does not share it. Close the camera there, or select a virtual camera instead — see Sharing one webcam.
"Camera permission required"
Windows is blocking camera access. Open Settings → Privacy & security → Camera and switch on Let desktop apps access your camera. The button in the overlay takes you there.
"Camera disconnected" or "No camera found"
Plug the camera in; the preview starts by itself. If you selected a specific camera that is no longer available, choose another in Settings.
I cannot click the overlay
Click-through is on. Press Ctrl + Alt + C, or right-click the tray icon and untick Click-through.
The overlay is gone
It is hidden to the tray. Click the tray icon or press Ctrl + Alt + V. If the icon is not visible, look behind the ^ arrow next to the clock.
"Preview Cam" is not in OBS's device list
- It is a camera, so it appears under Video Capture Device, not under Window Capture.
- Switch on Settings → Camera → Virtual camera for OBS in Preview Cam.
- Close and reopen the source's properties in OBS to refresh the list.
- If OBS runs as administrator, start it normally: the camera is registered for your user account, which elevated programs ignore.
The overlay is not in OBS's Window Capture list
Switch on Settings → Behavior → Allow window capture.
A hotkey does nothing
Another application has registered the same combination; Settings shows a warning icon next to it. Choose a different combination.
Reset everything
Quit Preview Cam and delete the folder %APPDATA%\uz.nurafshon\Preview Cam. The next start is like the first.
Something else
Open an issue and describe what you did and what happened.