AttributeError: 'VispyWidget' object has no attribute 'on_msg'

[yileichen123]

---

AttributeError Traceback (most recent call last)
in ()
----> 1 c.show()
2 app.run();

f:\anaconda3\vispy-master\vispy\app\canvas.py in show(self, visible, run)
427 Run the backend event loop.
428 """
--> 429 self._backend._vispy_set_visible(visible)
430 if run:
431 self.app.run()

f:\anaconda3\vispy-master\vispy\app\backends_ipynb_webgl.py in _vispy_set_visible(self, visible)
206 return
207 if self._widget is None:
--> 208 self._widget = VispyWidget()
209 self._widget.set_canvas(self._vispy_canvas)
210 display(self._widget)

f:\anaconda3\vispy-master\vispy\app\backends\ipython_widget.py in init(self, **kwargs)
60 def init(self, **kwargs):
61 super(VispyWidget, self).init(**kwargs)
---> 62 self.on_msg(self.events_received)
63 self.canvas = None
64 self.canvas_backend = None

AttributeError: 'VispyWidget' object has no attribute 'on_msg'