I have tried to find a solution online - nothing is working as far as PS and creative cloud.
LR is working and I was able to upgrade to 5.7 successfully - this is the same monthly subscription - PS has not worked since I upgraded to 2014 as part of the normal upgrade process.
I see MANY others are having the same problem. Maybe Adobe should start stop charging our accounts until this is fixed.
BLANK Cloud Screen http://forums.adobe.com/message/5484303 may help
-and step by step http://forums.adobe.com/thread/1440508?tstart=0
A chat session where an agent may remotely look inside your computer may help
Creative Cloud chat support (all Creative Cloud customer service issues)