Spinning wheel during camera check

This issue is caused by:  Another program, background process, or privacy setting  is preventing LockDown Browser from activating the camera.

Windows Users

Check whether you've enabled the correct privacy settings for your camera and microphone by following the below steps:

1. On the keyboard, click on the Windows key.
2. Search for Camera Privacy Settings.
3. Scroll to "Allow desktop apps to access your camera" and make sure "on" is selected. LockDown Browser should also appear in the list below. 
4. For Lenovo devices: Repeat the above process for your "Microphone Privacy Settings."

Then, you have to disable any anti-virus or firewall on your device that may be using your Camera, by searching for the application in your device and turning it off.

Mac Users

Grant LockDown Browser permission to access your camera and microphone by following the below steps:

1. Go to: System Preferences > Security and Privacy > Privacy
2. Click the lock icon in the lower left, then enter your admin password. 
3. Click on Camera in the left-hand menu and then click the check box next to LockDown Browser.
4. Perform this same action for your microphone

For more details please check this article.