macOS has strict security settings that require you to allow applications to use the camera. Open (or System Preferences). Go to Privacy & Security > Camera .

This is the #1 reason cameras appear "blocked." Your camera can only stream to .

Sometimes, a recent Windows update breaks the camera driver. This doesn't mean your camera is broken; it just needs a kickstart.

Many modern laptops, monitors, and even standalone webcams have a . This is a small sliding switch or ring around the lens.