Computer check can be failured because of incorrectly functioning camera. To troubleshoot It, you need to complete the following points:

· Check the camera indicator. If the camera indicator light next to the camera flashes green on your Mac notebook, contact Apple;

· Close all apps that using your camera. Press these three keys together: Option, Command, and Esc (Escape). Or choose Force Quit from the Apple menu in the upper-left corner of your screen.;

· Check settings «Screen Time». If you're using macOS Catalina and also use Screen Time, make sure your camera is turned on and apps that use the camera have time available.

    1. Choose Apple menu > System Preferences, then click Screen Time.

    2. Click Content & Privacy in the sidebar, then click Apps.

    3. Make sure the checkbox for Camera is selected. 

    4. Click App Limits in the sidebar. If you need to use your camera with an app in the list, make sure the checkbox for Limits is not selected.

· Give apps permission:

    1. Choose Apple menu > System Preferences, then click Security & Privacy.

    2. Click the Privacy tab, then click Camera in the sidebar.

    3. Select the checkbox next to the apps that you want to use your camera in. You might be prompted to quit and reopen an app before it can use your camera.

· Try to use your camera in another app. For example, if you can't use your camera in FaceTime, open Photo Booth.