If you downloaded a Mac application from the Internet and tried to have it installed, you may get a pop-up message saying that the app cannot be opened because it is from an unidentified developer.
This is due that OS X 10.8 Mountain Lion and 10.9 Mavericks include new features to improve security for users. One of the new default options prevents users from being able to install or launch applications that were not downloaded from the Mac App Store, or not digitally signed by the developers. That’s to say, you can only install apps from the Mac App Store and identified developers.
To get the unidentified apps installed onto Mountain Lion or Mavericks successfully, simply follow the steps below:
- Go to System Preferences > Security & Privacy
- Click the lock icon in the bottom left corner and enter the administrator username and password
- Under “Allow applications downloaded from”, select “Anywhere”