I'm having the same problem, I log in with the CC desktop App and I get a blank white screen. No spinning ball or anything. This seems to be a reoccurring problem.
I tried restarting, same thing. I'm using MacOS 10.10.4 if that helps.
Branching into a new discussion.
I believe you are referring to the blank white window of CC desktop app.
Please refer to the threads below where this issue has been addressed: