If you see similar error message during installation of an application on your Mac machine, then follow the instruction below to allow your machine to install the application.
Step 1 - Go to Security & Privacy.
Step 2 - Click the Open Anyway button in the General tab to confirm to open or install the app.
Step 3 - The warning prompt reappears, click Open.
The app is now saved as an exception to your security settings, and you can open it in the future by double-clicking it, just as you can any authorized app.