The error that you get in the console is saying that Unity cannot find an API that exists only in the Win8 version of Unity - metro is the (old) code name for the Win8 GUI. It’s really strange that you get this message on a Mac, since the Mac shouldn’t have any of the Win8 features. I’d be inclined to blow away you Unity install, and download a fresh copy of the installer, and install a fresh copy.
Then, regarding the crashing you see when you run the app that you have built, please use Console.app and see what errors OSX records when the app is launched. Post what you get here, and I suspect one of us can explain what’s happening.