Install error: “cannot be opened because it is from an unidentified developer”

This error occurs because your computer is set up such that it will only let programs install that have been vetted by Apple. This is general this is a good security measure, but it can sometimes cause issues like this.

Follow the steps below :

• Click OK.

• Press the Command and Spacebar keys, type Security & Privacy . Click the Open Anyway button in the General pane to confirm your intent to open the app.
• Click Open .