Log out of your Cloud account... Restart your computer... Log in to your paid Cloud account
-If you have more than one email, but sure you are using the one linked to your subscription
It's happening to me too. Trying to run Lr and Ps. All I get is a loop on the Sign In page of the App manager.
Actually, rebooting might help. I was just on chat with support. I've been using CC for years. Today it didn't work. You have to delete a number of folders in /Library and ~/Library (if you're on a Mac) and then kill all Adobe processes. Then restart the CC Manager. Apparently the local database can get corrupted.
If Adobe were smart, the CC/App Manager would detect a problem and allow you to reset the database. But rebooting might help.