Jupyter notebook: No connection to server because websocket connection fails

Question

I have just installed Jupyter over pip (Python version is 3.7.2) in Windows 10, started the jupyter server by calling jupyter notebook, created a new notebook w

Answer 1

Reset your jupyter notebook configuration file by use this below command to reset default config of jupyter_notebook_config.py

jupyter notebook --generate-config

Answer 2

The problem was that there was an incompatibility between the packages tornado 6 and notebook 5.7.4. notebook was updated on March 6th 2019 in order to solve this issue. Right now, the best way to solve it is the following:

Using pip

$ pip install -U jupyter

Using pipenv

$ pipenv update jupyter

Answer 3

This problem occurs when you install TensorFlow.js.

When you install TensorFlow.js, it also installs prompt-toolkit-1.0.14, which causes the problem.

After installing TensorFlow.js, you just have to install prompt-toolkit-3.0.5 to solve this problem by running the following code in your command prompt:

pip install prompt-toolkit==3.0.5

Answer 4

Don't downgrade tornado. Instead, force-reinstall jupyter.

pip3 install --force-reinstall upgrade jupyter

Ref: https://github.com/jupyter/notebook/issues/4439

Answer 5

The Jupyter Notebook 5.7.5 update should resolve issues with tornado 6. See the tweeted announcement and github release tag by the Jupyter team.

As of 03-06-19, both the docs and conda distribution are pending changes. You may however update using pip.

---

From the docs, upgrade with:

> pip install notebook --upgrade

Verify version:

> pip --version

Answer 6

I had the same problem, and following this vvk2001github https://github.com/jupyter/notebook/issues/4399 fixed it for me.

Uninstall tornado 6 and reinstall tornado 5.

sudo pip3 uninstall tornado
sudo pip3 install tornado==5.1.1

@kaleo gave this answer as well to similar question from @Jason Nichols