Mac OS X 10.8 and 10.9 will give you this error message when you try to launch any Mac app that didn’t come from the Mac App Store. This new security feature is called GateKeeper.
To launch the app once (and temporarily disable the error message):
- Right-click the app icon.
- Click Open.
- When the warning dialog appears, click Open.
To permanently disable the error message:
- Click the Apple menu.
- Click System Preferences...
- Click Security & Privacy.
- Click the General tab.
- Click the lock icon on the bottom and enter your Administrator password.
- In the list Allows apps downloaded from, click Anywhere.
- Close System Preferences.
- Launch the app normally.