HTTP 404: Not Found - Kernel does not exist

[Kinzowa]

Hello,

I'm running a Jupyter Notebook remotely with django-shell-plus and open it locally in my browser, but I'm regularly facing a problem : HTTP 404: Not Found - Kernel does not exist. I followed the recommendation from [this issue] but unfortunatly it doesn't solve my problem.(#4909)

Output

(env) user@ubuntu-2cpu-4gb-de-fra1:/var/www/app$ python manage.py shell_plus --notebook --no-browser 
[I 07:28:45.347 NotebookApp] Serving notebooks from local directory: /var/www/app
[I 07:28:45.347 NotebookApp] The Jupyter Notebook is running at:
[I 07:28:45.347 NotebookApp] http://localhost:8888/?token=ac388ddf14c9878471c47244a4111d12ed4048e838368050
[I 07:28:45.347 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 07:28:45.350 NotebookApp] 
    
    To access the notebook, open this file in a browser:
        file:///home/user/.local/share/jupyter/runtime/nbserver-19823-open.html
    Or copy and paste one of these URLs:
        http://localhost:8888/?token=ac388ddf14c9878471c47244a4111d12ed4048e838368050
[E 07:28:54.285 NotebookApp] Exception restarting kernel
    Traceback (most recent call last):
      File "/home/user/.local/lib/python3.7/site-packages/notebook/services/kernels/handlers.py", line 85, in post
        yield gen.maybe_future(km.restart_kernel(kernel_id))
      File "/home/user/.local/lib/python3.7/site-packages/notebook/services/kernels/kernelmanager.py", line 285, in restart_kernel
        self._check_kernel_id(kernel_id)
      File "/home/user/.local/lib/python3.7/site-packages/notebook/services/kernels/kernelmanager.py", line 364, in _check_kernel_id
        raise web.HTTPError(404, u'Kernel does not exist: %s' % kernel_id)
    tornado.web.HTTPError: HTTP 404: Not Found (Kernel does not exist: ac442b4a-daa5-4b42-925a-caad7f9718a9)
[E 07:28:54.288 NotebookApp] {
      "Host": "localhost:8888",
      "Connection": "keep-alive",
      "Content-Length": "0",
      "Accept": "application/json, text/javascript, */*; q=0.01",
      "Dnt": "1",
      "X-Requested-With": "XMLHttpRequest",
      "X-Xsrftoken": "2|8bbbbb7d|0518917637b894ceb93c9b1c3e362acc|1632481357",
      "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.81 Safari/537.36",
      "Sec-Gpc": "1",
      "Origin": "http://localhost:8888",
      "Sec-Fetch-Site": "same-origin",
      "Sec-Fetch-Mode": "cors",
      "Sec-Fetch-Dest": "empty",
      "Referer": "http://localhost:8888/notebooks/Untitled.ipynb",
      "Accept-Encoding": "gzip, deflate, br",
      "Accept-Language": "en-GB,en-US;q=0.9,en;q=0.8",
      "Cookie": "_xsrf=2|8bbbbb7d|0518917637b894ceb93c9b1c3e362acc|1632481357; username-localhost-8888=\"2|1:0|10:1634463998|23:username-localhost-8888|44:ZTc3NjU3OTI4YjkzNGIzZjlkMTQ5NjE5OWY5NjZkNmY=|69d0615da498719b09ac771e107ed6dec7fe215807445c1786d36020db3b2598\""
    }
[E 07:28:54.288 NotebookApp] 500 POST /api/kernels/ac442b4a-daa5-4b42-925a-caad7f9718a9/restart (127.0.0.1) 3.44ms referer=http://localhost:8888/notebooks/Untitled.ipynb
[W 07:28:54.348 NotebookApp] 404 DELETE /api/sessions/f997b2ad-0c49-4ff8-a42c-84b02034120c (127.0.0.1): Session not found: session_id='f997b2ad-0c49-4ff8-a42c-84b02034120c'
[W 07:28:54.349 NotebookApp] Session not found: session_id='f997b2ad-0c49-4ff8-a42c-84b02034120c'
[W 07:28:54.349 NotebookApp] 404 DELETE /api/sessions/f997b2ad-0c49-4ff8-a42c-84b02034120c (127.0.0.1) 1.99ms referer=http://localhost:8888/notebooks/Untitled.ipynb
[I 07:29:54.904 NotebookApp] Kernel started: af1323c0-d216-4d3a-a149-5ca2d4920ec0
/usr/lib/python3.7/json/encoder.py:257: UserWarning: date_default is deprecated since jupyter_client 7.0.0. Use jupyter_client.jsonutil.json_default.
  return _iterencode(o, 0)

Package version

tornado==5.1.1
jupyter==1.0.0
jupyter-client==7.0.6
jupyter-console==6.4.0
jupyter-core==4.8.1
jupyterlab-pygments==0.1.2
jupyterlab-widgets==1.0.2

Help would be appreciated,

Best,

[Kinzowa]

I upgraded notebook with the latest version and it looks better now.

pip3 install --upgrade notebook
Successfully installed notebook-6.4.4 tornado-6.1