Quit the video app that’s having trouble and open Photo Booth. It already has camera access on a Mac. If you can see yourself there, check camera access in the original app or website. If Photo Booth also fails, check Screen Time and restart the Mac.
01If the picture works in Photo Booth
Section linkOpen System Settings → Privacy & Security → Camera and allow the affected app if it appears. Quit and reopen it after changing access. If the app is missing from the list, try starting its video preview so it can request access. For a website in Safari, open Safari → Settings → Websites → Camera and check the setting for that site.
02If the camera fails in Apple apps too
Section linkIf you use Screen Time, open System Settings → Screen Time → Content & Privacy → App Restrictions and check that Camera is allowed. Also check App Limits for the app you’re testing. Install any available macOS update and restart the Mac, then reopen Photo Booth to test the picture.
03What the green light can tell you
Section linkA steady green light indicates camera use. Quit the apps using the camera and the light should go out. If the built-in camera still fails across apps after the checks above, or the light next to it flashes green, Apple says the Mac may need service.
Sources & further reading
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