When installing Parallels Desktop application, an error message appears: "The installer is not recognized" or "This dmg file is not recognized".
Security and Privacy setting "Allow apps downloaded from:" is not set correctly.
- Go to the Mac's System Preferences window: from the Apple menu at the upper-left corner of the screen > System Preferences...
- Open "Security & Privacy";
- Under Allow apps downloaded from:, choose Anywhere;
- Proceed with the installation.