OS X Mountain Lion can't open the Backup Client package for installation from an unidentified developer
When trying to install the Attix5 Pro Backup Client you get a dialog showing:
OS X 10.8 features a new security feature called Gatekeeper which prevents the installation of malware by controlling the types of software that can be installed.
The feature is enabled by default when the OS is installed and prevents the user from installing apps that do not originate from the App Store or when the package does not include a Developer ID.
To allow the installation of the Attix5 Pro Backup Client you can configure Gatekeeper to allow the applications from "Anywhere".
Note: We have found that the installation is only intercepted by Gatekeeper when it has been downloaded and installed via a download link from the Mac itself. It does not intervene when the *.dmg has been copied to the Mac platform or if it was installed from a Samba file share.