Same here, blank screen for Creative Cloud !
I'm running Win8-64, have been using Creative Cloud without any problem for a while under the same conditions, but now (and i beleive since the last update of CC) the CC window remains blank, before even letting me log in.
I've been trying all the fixes listed above (double checked that there aren't any special character on my profile, renamed the folder OOBE under programs/common files/adobe ; deleted the opm.db; even doing so, then uninstall CC, reboot and reinstall) nothing will fix that.
Though i'm also running Creative Cloud on a laptop under Win7-64, and it's working fine on this pc.