since I have the Adobe Creative Cloud desktop app installed on my new Mac (about 1 month ago), it opens an additional empty window on each launch. Since the update to the CC2014 I can observe this behavior in some Adobe applications like Dreamweaver, too. (but not Photoshop)
I chatted with the Adobe and the Apple support, but their solutions had no effect.
What they have tried:
The only thing that has helped was to create a new user. But this is not the right solution. Funnily enough, I had this problem when I installed the CC application for the first time on my Mac. It was one of the first programs on the new OS. Maybe the problem has something to do with my user account, but I had the problem, even under Windows.
I hope you can help me! Have a great weekend!