If you see either of these errors then you need to set Gatekeeper to allow applications downloaded from "Anywhere". 

  1. Open the System Preferences. This can be done by either clicking on the System Preferences icon in the Dock or by going to Apple Menu > System Preferences.
  2. Open the Security & Privacy pane by clicking Security & Privacy.
  3. Make sure that the General tab is selected. Click the icon labeled Click the lock to make changes.

4. Enter your username and password into the prompt that appears and click Unlock.

5. Under the section labeled Allow applications downloaded from:, select Anywhere. On the prompt that appears, click Allow From Anywhere.

Also See this Gatekeeper guide on apple.com