I got the same issue. The window is just there and cant be closed normally except by taks manager.
The install of adobe creative cloud is broken. You need to reinstall creative cloud app.
Have done same thing multiple times, same results. Have used the cleaner tool, cleaned registry, restarted, reinstalled, same results.
It seems the cloud-window is related to an inconsistency with Apple-Tools (the tools you have with an iphone).
Upon update today I got my "Core"-window again
So its either a bug by Adobe with Apple or vice versa - or so it seems.
Thank you Adobe/Apple for these problems.