crash if no QApplication

[hanWolf3D]

• add somehting like this
• test in a non bqt wrapped blender, ensure its the first qt tool we test

def show():
    app = QtWidgets.QApplication.instance()
    
    exec = False
    if not app:
        exec = True
        app = QtWidgets.QApplication()
    
    global window
    window = MainWindow()
    window.show()

    if exec:
        app.exec_()

    return window

[hanWolf3D]

we can also add a try except to the menu to catch other errors