Popular quiz app QuizUp has a small but important update available for both Windows and Windows Phone 8.1 versions of the game. Though the update itself is over two weeks old, Microsoft has recently fixed a store bug that prevented users from updating the game.
This update corrects a bug that prevented users on both desktop and mobile from actually playing the game. A bug in a previous update left many users unable to play. Note that the current changelog for QuizUp represents an update that rolled out in July.
You grab the update from the Windows Store now.