This error occurs when the in-game shop is currently closed.
Your Battle.net account does not have access to this beta content.
How to resolve this issue when installing or updating a game
You have attempted to connect to an invalid server. If this problem persists, please contact Customer Support.
How to swap email addresses between two accounts
Standalone patches are downloaded outside of the game launcher or the Battle.net desktop app.
Blizzard servers could not be reached or may be offline.