I'm trying to install Adobe Digital Editions on my Mac, but when I click "install" during the installation process, nothing happens. I've tried versions 3.0, 2.0, and 1.72, and it's exactly the same. There's no error message. I've checked and I don't already have it installed. I have a MacBook Air with OSX 10.9.2.
Did you look for error messages in the Console application? This is where you will find a log of everything that your computer does (well most of it). You can open the Console by going to spotlight, typing in Console, and opening the application that it finds.