Board Thread:Questions and Answers/@comment-25309891-20150217182535/@comment-24956068-20150217193441

Does it happen frequently? Does the black background only appear in a specific/certain stages or performing certain actions?

I think this bug will not affect the result of your game at all, but if this one made you really disturbed and disconcerned, I may suggest uninstalling and reinstalling the game, or sending an inquiry to Customer Support.