Can't be opened because it is from an unidentified developer (Mac Error Fix)

Here's how to simply fix the error: "the-application.dmg" can't be opened because it is from an unidentified developer. Run the application where it shows the error message and do not close it.

1. Go to System Preferences

2. Go to Security & Privacy and click on Open Anyway

3. Put your password

4. It should automatically run