Hello, So I have the public beta of Yosemite installed. But my iTunes was still its original version, so when I clicked on "Update" in the App store, it would display a download bar for about half a second and then disappear changing the "Update" button to "Installed" and then changing back to "Update" 3 seconds later. Everytime I click on Update, it also adds iTunes as updated recently list. No error is displayed. How can I download iTunes 12 and fix this issue. Thanks.