Be sure that your Mac is running OS X Mavericks. If you don't have OS X Mavericks, you can download it free from the Mac App Store. We recommend installing OS X Yosemite Beta on a secondary Mac, since it may contain errors or inaccuracies. Please be sure to back up your Mac using Time Machine before you install the beta. This is beta software that is still in development, which means some applications and services may not work as expected. Some features require iOS 8, which is not being offered as part of the OS X Beta Program.
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