Pretty sure this happened after I rolled back OSX El-Capitan to Yosemite (necessary to keep using M$ office)...
My CC folder has disappeared from Finder. And in the CC App preferences, under "Files" if I select Sync "On" the Folder location remains greyed-out. I cannot specify it and it does not re-appear toggling off to on.
The files are all still there viewed online in browser.
Your roll back to OS X 10.10 could have well broken things on your Mac. Your Creative Cloud Files folder will still be there but could well be hidden. Are you logged in? do you use different Adobe iD's? , if you log out of once Adobe iD and log into another the Creative Cloud File folder will be hidden for the logged out use, then re appear once that user logs back in. Have you tried a reinstall of Creative Cloud to solve this issue, this would be the first thing to try.
There are no guarantees that things will work as they once did after a full system rollback like this.