title: Jupyter Notebook dead Kernel after Anaconda update
body: <p>I got the following problem. After update Anaconda because I got an error to import skimage.io to a project in Jupyter Notebook an even a greater error appear - Dead Kernel. Right now I could not ever start a project because the Jupyter gives the following error is: </p>
  
  <pre><code>Copy/paste this URL into your browser when you connect for the first time,
  to login with a token:
      http://localhost:8888/? 
  token=aaf85a5e18489792c87cce65d7a53a0263cd5c08cc7248b 6
  [I 00:55:13.451 NotebookApp] Accepting one-time-token-authenticated 
  connection from ::1
  [I 00:55:31.607 NotebookApp] Kernel started: 608d2190-59e6-4888-b09a- 
  e616f67bd5b4
  Traceback (most recent call last):
  ERROR:tornado.general:Uncaught exception in ZMQStream callback
  Traceback (most recent call last):
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\zmq\eventloop\zmqstream.py", line 432, in _run_callback
  callback(*args, **kwargs)
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\tornado\stack_context.py", line 276, in null_wrapper
  return fn(*args, **kwargs)
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 283, in dispatcher
  return self.dispatch_shell(stream, msg)
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 233, in dispatch_shell
  self.pre_handler_hook()
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 248, in pre_handler_hook
  self.saved_sigint_handler = signal(SIGINT, default_int_handler)
  File "C:\Program Files\Anaconda3\lib\signal.py", line 47, in signal
  handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
  ValueError: signal only works in main thread  File "C:\Program 
  Files\Anaconda3\lib\runpy.py", line 193, in _run_module_as_main
  "__main__", mod_spec)
  
  File "C:\Program Files\Anaconda3\lib\runpy.py", line 85, in _run_code
  exec(code, run_globals)
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel_launcher.py", 
  line 16, in &lt;module&gt;
  app.launch_new_instance()
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\traitlets\config\application.py", line 658, in launch_instance
  app.start()
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelapp.py", 
  line 477, in start
  ioloop.IOLoop.instance().start()
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\tornado\platform\asyncio.py", line 112, in start
  self.asyncio_loop.run_forever()
  ERROR:tornado.general:Uncaught exception in zmqstream callback
  Traceback (most recent call last):
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\zmq\eventloop\zmqstream.py", line 450, in _handle_events
  self._handle_recv()
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\zmq\eventloop\zmqstream.py", line 480, in _handle_recv
  self._run_callback(callback, msg)
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\zmq\eventloop\zmqstream.py", line 432, in _run_callback
  callback(*args, **kwargs)
  File "C:\Program Files\Anaconda3\lib\site- 
  packages\tornado\stack_context.py", line 276, in null_wrapper
  return fn(*args, **kwargs)
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 283, in dispatcher
  return self.dispatch_shell(stream, msg)
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 233, in dispatch_shell
  self.pre_handler_hook()
  File "C:\Program Files\Anaconda3\lib\site-packages\ipykernel\kernelbase.py", 
  line 248, in pre_handler_hook
  self.saved_sigint_handler = signal(SIGINT, default_int_handler)
  File "C:\Program Files\Anaconda3\lib\signal.py", line 47, in signal
  handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
  ValueError: signal only works in main thread  File "C:\Program   
  Files\Anaconda3\lib\asyncio\base_events.py", line 409, in run_forever
  </code></pre>