Doors located diagonally to each other are a no-no in feng shui because this causes loss of energy which can disturb the harmony and balance in a home. Two small mirrors can remedy the situation. Place a mirror next to each door (opposite the other door’s opening.) This balances the tension and guides the flow of chi in healthy ways.
Source: Feng Shui Symbols by Christine M. Bradler and Joachim Alfred P. Scheiner.