Check that another app isn't using your device's camera. If one is, close that app to remove the black screen on FaceTime. Make sure the camera lens isn't blocked.

Learn how to use the multi-app camera feature in Windows 11 to allow multiple apps to use a camera or built-in webcam simultaneously.

If you open the Camera app and see a Can't start your camera error with error code 0xA00F429E (0x80131505) on Windows 11/10, use these fixes.