Safe Exam Browser Steps
Step 1. On the Mac open up Finder, and Applications, and double click on the Application called NCTest.seb that is a grey icon (circled below)
Step 2. You will get a popup that says "Safe Exam Browser" would like to access files in your Documents Folder (pictured below) click OK
Step 3. Once Safe Exam Browser Launches, you will get a popup that says SEB Re-Configured, click "Continue" on that popup (Pictured Below)
After this is completed you should be able to use Safe Exam Browser.