crashes when almost click any thing

[fanhuanji]

Environment Info

Pip is not installed

Traceback

Traceback (most recent call last):
  File "E:\Python36x64\lib\site-packages\kivy\core\window\window_sdl2.py", line 727, in mainloop
    self._mainloop()
  File "E:\Python36x64\lib\site-packages\kivy\core\window\window_sdl2.py", line 460, in _mainloop
    EventLoop.idle()
  File "E:\Python36x64\lib\site-packages\kivy\base.py", line 340, in idle
    self.dispatch_input()
  File "E:\Python36x64\lib\site-packages\kivy\base.py", line 325, in dispatch_input
    post_dispatch_input(*pop(0))
  File "E:\Python36x64\lib\site-packages\kivy\base.py", line 291, in post_dispatch_input
    wid.dispatch('on_touch_up', me)
  File "kivy\_event.pyx", line 707, in kivy._event.EventDispatcher.dispatch
  File "E:\Python36x64\lib\site-packages\kivy\uix\behaviors\button.py", line 179, in on_touch_up
    self.dispatch('on_release')
  File "kivy\_event.pyx", line 703, in kivy._event.EventDispatcher.dispatch
  File "kivy\_event.pyx", line 1214, in kivy._event.EventObservers.dispatch
  File "kivy\_event.pyx", line 1098, in kivy._event.EventObservers._dispatch
  File "E:\Python36x64\lib\site-packages\kivy\lang\builder.py", line 64, in custom_callback
    exec(__kvlang__.co_value, idmap)
  File "Y:\kivy-designer-master\designer\designer.kv", line 200, in <module>
    on_release: root.dispatch('on_ok')
  File "kivy\_event.pyx", line 703, in kivy._event.EventDispatcher.dispatch
  File "kivy\_event.pyx", line 1214, in kivy._event.EventObservers.dispatch
  File "kivy\_event.pyx", line 1138, in kivy._event.EventObservers._dispatch
  File "Y:\kivy-designer-master\designer\utils\utils.py", line 198, in wrapper
    f(*args, **kwargs)
  File "Y:\kivy-designer-master\designer\app.py", line 566, in _perform_reload
    self._perform_open(self.project_manager.current_project.path)
  File "Y:\kivy-designer-master\designer\app.py", line 989, in _perform_open
    self.designer_git.load_repo(file_path)
  File "Y:\kivy-designer-master\designer\tools\git_integration.py", line 121, in load_repo
    self._update_menu()
  File "Y:\kivy-designer-master\designer\tools\git_integration.py", line 128, in _update_menu
    self.remove_children()
  File "Y:\kivy-designer-master\designer\uix\contextual.py", line 491, in remove_children
    self.container.remove_widget(child)
AttributeError: 'NoneType' object has no attribute 'remove_widget'

End of Traceback