Based on my experience with the error 11007, I would rate SimCity BuildIt 2/5 stars. While the game has potential, the persistent error has significantly impacted my enjoyment of the game.

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Result: After clearing cache and reconnecting my account, the game loaded normally and Error 11007 stopped appearing.

The message means the server received a key, checked it against its database, and said, "This key does not match any active session, or the token has expired."