Did you use CS5 or CS6 in the past? Did you set those apps to use offline help only so that you didn't have to watch Adobe Air update itself every time you tried to open Help? If so, there might be an old Adobe Help (CS5 / CS6) preference lingering on your machine. You wouldn't think CC would respect it, but you would be wrong. I had to install old Adobe Help (for CS5 / CS6) and change the pref.
I downloaded the outmoded Adobe Help app by way of: http://www.adobe.com/support/chc/?helpcfg=http://help.adobe.com/HelpCfg/en_US/Dreamweaver. helpcfg&url=http://helpx.adobe.com/en/dreamweaver/topics.html&product=dreamweaver