If you are continuing to experience difficulties with being unable to sign into the Creative Cloud desktop application then please see Unable to sign in to Creative Cloud after latest update http://helpx.adobe.com/creative-cloud/kb/unable-login-creative-cloud-248.html
Please follow this step by step procedure:
1. Open a Finder window, select Go>Go to folder option, type in ~/Library and hit enter.
2: Now navigate to Application Support/Adobe/OOBE/.. folder.
3: Delete opm file under OOBE.
4: Rename OOBE to OOBEold.
5: Check if you have AAMupdater in the same location.
6: Please rename it to AAMupdaterold.
7: Click on gear icon on Creative Cloud desktop app and choose Quit Creative Cloud.
8: Then launch it, sign-in and click on Apps tab.
Unfortunatly it made no difference.
Thanks for the Time Travel back to DOS though
Thanks Richa, that worked.
On PC, so slightly different path..
Just for anyone else that may have this issue on a PC (Win 8.1)