Traceback (most recent call last):
File "C:\Anaconda3\envs\jupyter-env\lib\site-packages\tornado\websocket.py", line 546, in _run_callback
result = callback(*args, **kwargs)
File "C:\Anaconda3\envs\jupyter-env\lib\site-packages\notebook\services\kernels\handlers.py", line 262, in open
super(ZMQChannelsHandler, self).open()
File "C:\Anaconda3\envs\jupyter-env\lib\site-packages\notebook\base\zmqhandlers.py", line 176, in open
self.send_ping, self.ping_interval, io_loop=loop,
TypeError: __init__() got an unexpected keyword argument 'io_loop'
対応
以下のページを参考に、tornado のバージョンを落としたら動いた。
http://thinkami.hatenablog.com/entry/2018/08/04/102850