Jupyter notebook kernel not connecting

Question

I have previously used Jupyter Notebook (python 2 and 3) on my mac. After not using it for a while, there seems to be a problem I am unable to fix. When starting the notebook from terminal using the command Jupyter notebook, and then select a notebook I want to work with, I get the 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."

I am positive this has nothing to do with my internet connection (I have tried 2 machines connected to different networks).

I have read that the browser could be the problem, therefore I have installed Chrome and Firefox. However, I get this error when I am using Safari, Chrome, and Firefox.

Then I read about it being a proxy issue. I have tried to add the server address of the notebook to the No proxy fields of the advanced network preferences of my mac, and of the advanced setting on Firefox.

The only thing I can think of is that I am entering the wrong server address?

I do not know much about setting and errors in general, hopefully someone can provide me with some alternative options to get Jupyter working again.

Terminal output:

ValueError: signal only works in main thread
ERROR:tornado.application:Exception in callback <functools.partial object at 0x111e2b208>
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 <lambda>
    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 <module>
    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 <module>
    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 <module>
    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 <module>
    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

Answer 1

Running the following version of jupyter and tornado seemed to solve the issue:

Jupyter: 4.4.0

Tornado: 4.5.3

I needed to downgrade my version of tornado (which was 5.0.2)

Answer 2

I found a way out, Installing Python on my PC solved it. I didn't install python before installing anaconda

Answer 3

I faced this problem too. My problem was because of a custom module name. I named the module 'copy.py.' My issue was solved when I renamed it.

Answer 4

I was also facing the kernal related issues and all my problems were solved by installing jupyter notebook from anaconda navigator.

So,The best way to handle jupyter notebook related problems is to install jupyter notebook from anaconda navigator for your environment in which you want to run jupyter notebook. If you will install jupyter notebook from anaconda navigator then you will not face any problem.