Permissions and security settings on specific Macs, might prevent LockDown Browser from restarting the Notifications Center and Siri during a normal close of the browser after submitting an exam.
We recommend the following steps to restore the default settings on a Macintosh system:
1. Start the system from a power down (not Sleep).
2. Start LockDown Browser
3. Immediately quit LockDown Browser
If the Notifications Centre does not restart right away, these steps usually work:
Open Terminal and enter the following commands:
launchctl load -w /System/Library/LaunchAgents/com.apple.notificationcenterui.plist
killall SystemUIServer
These are the same steps that LockDown Browser uses to restart the Notifications Center.