[WindowsCentral.com]

If you're no longer able to download digital content from the Windows Store, you probably reached your device limit. Here's how to resolve the issue.

Windows 10 includes a new improved experience for getting and managing apps, games, music, shows and movies from the Windows Store. However, along with these new refinements, Microsoft introduced a stricter device limit than the one in Windows 8.1.
Basically, "device limit" refer to the total number of devices (desktop computers, laptops, tablets and phones) that you can use to access apps, games, and other digital content you download or purchase with a Microsoft account from the Store.

Full story from the WindowsCentral blog...