Overview
By default, your Mac may be configured to only allow the installation of applications approved by Apple. To install certain applications, you may need to change your system settings to allow other application to be installed. Once you've completed the installation, you can revert to your preferred settings.
Disable Gatekeeper
- Click on the Apple Icon in the upper left corner of the screen and open System Preferences
- Click on Security & Privacy
- Under Allow Applications Downloaded From, select Anywhere
Configure Gatekeeper
For more information about Gatekeeper, please see Apple's Knowledge Base article here.