El núcleo del cuaderno Jupyter no se conecta

Anteriormente he usado Jupyter Notebook (python 2 y 3) en mi mac. Después de no usarlo por un tiempo, parece que hay un problema que no puedo solucionar. Al iniciar el notebook desde la terminal con el comando Jupyter notebook , y luego seleccionar un notebook con el que quiero trabajar, aparece el error:

 "A connection to the notebook server could not be established. The notebook will continue trying to reconnect. Check your network connection or notebook server configuration." 

Estoy seguro de que esto no tiene nada que ver con mi conexión a Internet (he intentado 2 máquinas conectadas a diferentes redes).

He leído que el navegador podría ser el problema, por lo tanto, he instalado Chrome y Firefox. Sin embargo, recibo este error cuando uso Safari, Chrome y Firefox.

Luego leí que era un problema de proxy. He intentado agregar la dirección del servidor del portátil a los No proxy fields de las preferencias de red avanzadas de mi mac y de la configuración avanzada en Firefox.

¿Lo único en lo que puedo pensar es que estoy ingresando la dirección de servidor incorrecta?

No sé mucho acerca de la configuración y los errores en general, espero que alguien pueda brindarme algunas opciones alternativas para que Jupyter vuelva a funcionar.

Salida de terminal:

 ValueError: signal only works in main thread ERROR:tornado.application:Exception in callback  Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/ioloop.py", line 759, in _run_callback ret = callback() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/stack_context.py", line 276, in null_wrapper return fn(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/zmq/eventloop/zmqstream.py", line 536, in  self.io_loop.add_callback(lambda : self._handle_events(self.socket, 0)) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/zmq/eventloop/zmqstream.py", line 450, in _handle_events self._handle_recv() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/zmq/eventloop/zmqstream.py", line 480, in _handle_recv self._run_callback(callback, msg) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/stack_context.py", line 276, in null_wrapper return fn(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher return self.dispatch_shell(stream, msg) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell self.pre_handler_hook() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelbase.py", line 248, in pre_handler_hook self.saved_sigint_handler = signal(SIGINT, default_int_handler) ValueError: signal only works in main thread [I 19:03:26.685 NotebookApp] KernelRestarter: restarting kernel (1/5), new random ports Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 174, in _run_module_as_main "__main__", fname, loader, pkg_name) File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 72, in _run_code exec code in run_globals File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel_launcher.py", line 16, in  app.launch_new_instance() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/traitlets/config/application.py", line 658, in launch_instance app.start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelapp.py", line 477, in start ioloop.IOLoop.instance().start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/ioloop.py", line 928, in start raise RuntimeError("IOLoop is already running") RuntimeError: IOLoop is already running [I 19:03:29.696 NotebookApp] KernelRestarter: restarting kernel (2/5), new random ports Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 174, in _run_module_as_main "__main__", fname, loader, pkg_name) File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 72, in _run_code exec code in run_globals File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel_launcher.py", line 16, in  app.launch_new_instance() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/traitlets/config/application.py", line 658, in launch_instance app.start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelapp.py", line 477, in start ioloop.IOLoop.instance().start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/ioloop.py", line 928, in start raise RuntimeError("IOLoop is already running") RuntimeError: IOLoop is already running [I 19:03:32.712 NotebookApp] KernelRestarter: restarting kernel (3/5), new random ports Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 174, in _run_module_as_main "__main__", fname, loader, pkg_name) File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 72, in _run_code exec code in run_globals File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel_launcher.py", line 16, in  app.launch_new_instance() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/traitlets/config/application.py", line 658, in launch_instance app.start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelapp.py", line 477, in start ioloop.IOLoop.instance().start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/ioloop.py", line 928, in start raise RuntimeError("IOLoop is already running") RuntimeError: IOLoop is already running [W 19:03:33.717 NotebookApp] Timeout waiting for kernel_info reply from 2cf24420-719b-4666-ad9f-fcdf8db505f3 [E 19:03:33.721 NotebookApp] Uncaught exception in /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/websocket.py", line 498, in _run_callback result = callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/notebook/services/kernels/handlers.py", line 262, in open super(ZMQChannelsHandler, self).open() File "/Users/xxx/anaconda2/lib/python2.7/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' [E 19:03:34.749 NotebookApp] Uncaught exception in /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/websocket.py", line 498, in _run_callback result = callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/notebook/services/kernels/handlers.py", line 262, in open super(ZMQChannelsHandler, self).open() File "/Users/xxx/anaconda2/lib/python2.7/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' [I 19:03:35.724 NotebookApp] KernelRestarter: restarting kernel (4/5), new random ports [E 19:03:35.771 NotebookApp] Uncaught exception in /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/websocket.py", line 498, in _run_callback result = callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/notebook/services/kernels/handlers.py", line 262, in open super(ZMQChannelsHandler, self).open() File "/Users/xxx/anaconda2/lib/python2.7/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' Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 174, in _run_module_as_main "__main__", fname, loader, pkg_name) File "/Users/xxx/anaconda2/lib/python2.7/runpy.py", line 72, in _run_code exec code in run_globals File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel_launcher.py", line 16, in  app.launch_new_instance() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/traitlets/config/application.py", line 658, in launch_instance app.start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/ipykernel/kernelapp.py", line 477, in start ioloop.IOLoop.instance().start() File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/ioloop.py", line 928, in start raise RuntimeError("IOLoop is already running") RuntimeError: IOLoop is already running [E 19:03:36.791 NotebookApp] Uncaught exception in /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/websocket.py", line 498, in _run_callback result = callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/notebook/services/kernels/handlers.py", line 262, in open super(ZMQChannelsHandler, self).open() File "/Users/xxx/anaconda2/lib/python2.7/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' [E 19:03:37.810 NotebookApp] Uncaught exception in /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels Traceback (most recent call last): File "/Users/xxx/anaconda2/lib/python2.7/site-packages/tornado/websocket.py", line 498, in _run_callback result = callback(*args, **kwargs) File "/Users/xxx/anaconda2/lib/python2.7/site-packages/notebook/services/kernels/handlers.py", line 262, in open super(ZMQChannelsHandler, self).open() File "/Users/xxx/anaconda2/lib/python2.7/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' [W 19:03:38.733 NotebookApp] KernelRestarter: restart failed [W 19:03:38.733 NotebookApp] Kernel 2cf24420-719b-4666-ad9f-fcdf8db505f3 died, removing from map. [W 19:03:38.830 NotebookApp] 404 GET /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels?session_id=3F75F379F865488D8379D3BB7FC0BF0F (::1): Kernel does not exist: 2cf24420-719b-4666-ad9f-fcdf8db505f3 [W 19:03:38.838 NotebookApp] 404 GET /api/kernels/2cf24420-719b-4666-ad9f-fcdf8db505f3/channels?session_id=3F75F379F865488D8379D3BB7FC0BF0F (::1) 12.00ms referer=None [W 19:03:40.859 NotebookApp] Replacing stale connection: 2cf24420-719b-4666-ad9f-fcdf8db505f3:3F75F379F865488D8379D3BB7FC0BF0F 

Ejecutar la siguiente versión de jupyter y tornado pareció resolver el problema:

Jupyter: 4.4.0

Tornado: 4.5.3

Necesitaba degradar mi versión de tornado (que era 5.0.2)