def getNextQuestionWindow(self, event):
        if self.fr.winfo_exists():
            self.destroyQuestionWindow()
            self.createQuestionWindow()
Check there is a valid input and/or output volume selected. Otherwise show a warning message
dataset/ETHPy150Open christabella/pokepython/gamelib/gui.py/applicationGUI.getNextQuestionWindow--crossover with--dataset/ETHPy150Open acil-bwh/SlicerCIP/Scripted/CIP_LesionModel/CIP_LesionModel.py/CIP_LesionModelWidget.__validateInputVolumeSelection__