error while opening .kv file in kivy-designer 1.10 on MacPro

[iruriksl]

Environment Info

Pip is not installed

Traceback

Traceback (most recent call last):
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/core/window/window_sdl2.py", line 663, in mainloop
    self._mainloop()
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/core/window/window_sdl2.py", line 405, in _mainloop
    EventLoop.idle()
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/base.py", line 342, in idle
    self.dispatch_input()
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/base.py", line 327, in dispatch_input
    post_dispatch_input(*pop(0))
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/base.py", line 293, in post_dispatch_input
    wid.dispatch('on_touch_up', me)
  File "kivy/_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7726)
    return handler(*largs, **kwargs)
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/uix/behaviors/button.py", line 179, in on_touch_up
    self.dispatch('on_release')
  File "kivy/_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7681)
    if observers.dispatch(self, None, largs, kwargs, 1):
  File "kivy/_event.pyx", line 1225, in kivy._event.EventObservers.dispatch (kivy/_event.c:13524)
    result = self._dispatch(
  File "kivy/_event.pyx", line 1109, in kivy._event.EventObservers._dispatch (kivy/_event.c:12356)
    return f(*fargs, **kwargs)
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/lang/builder.py", line 64, in custom_callback
    exec(__kvlang__.co_value, idmap)
  File "/Users/pinkgautam/Workspace/appbuild/sources/kivy-designer/designer/designer.kv", line 217, in <module>
    on_release: root.dispatch('on_save')
  File "kivy/_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:7681)
    if observers.dispatch(self, None, largs, kwargs, 1):
  File "kivy/_event.pyx", line 1225, in kivy._event.EventObservers.dispatch (kivy/_event.c:13524)
    result = self._dispatch(
  File "kivy/_event.pyx", line 1149, in kivy._event.EventObservers._dispatch (kivy/_event.c:13050)
    return f(obj, *largs, **kwargs)
  File "designer/app.py", line 872, in save_and_close
    self._perform_close_project()
  File "designer/app.py", line 892, in _perform_close_project
    self.add_widget(self.start_page, 1)
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/uix/floatlayout.py", line 140, in add_widget
    return super(FloatLayout, self).add_widget(widget, index)
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/uix/layout.py", line 97, in add_widget
    return super(Layout, self).add_widget(widget, index)
  File "/Applications/Kivy.app/Contents/Resources/kivy/kivy/uix/widget.py", line 532, in add_widget
    % (widget, parent))
WidgetException: Cannot add <designer.components.start_page.DesignerStartPage object at 0x11875cad0>, it already has a parent <designer.app.Designer object at 0x1177bb1a0>

End of Traceback