IPython Notebook WebSocket connection failed

Question

With Chrome/Firefox and IPython 1.1 under Windows 7 64bit I've got the error "WebSocket connection failed" on opening an existing IPython notebook if using automatic proxy configuration (with authentication) though the configuration file contains exception for localhost.

I poked a little bit around in Chrome (30) and found in the Javascript console (F12):

Kernel started:  aec48410-068f-424f-8fc1-8fd229409e70 kernel.js:110
Starting WebSockets: ws://127.0.0.1:8888/kernels/aec48410-068f-424f-8fc1-8fd229409e70 kernel.js:143
WebSocket connection to 'ws://127.0.0.1:8888/kernels/aec48410-068f-424f-8fc1-8fd229409e70/iopub' failed: WebSocket is closed before the connection is established.
WebSocket connection to 'ws://127.0.0.1:8888/kernels/aec48410-068f-424f-8fc1-8fd229409e70/stdin' failed: WebSocket is closed before the connection is established.
WebSocket connection failed:  ws://127.0.0.1:8888/kernels/aec48410-068f-424f-8fc1-8fd229409e70 

Obviously the websocket server has been started and it is the right adress (same as output of ipython-notebook)

Any ideas? Thanks!

Answer 1

It is about proxy configuration: We have a proxy that needs authentication and it is normally automatically configured by a central configuration file.

In this file there is an exception for localhost but for some reason this does not work.

Manually configuring the proxy with authentication and adding localhost as an exception did the job. And that was the difference between Firefox and Chrome - I forgot that I configured them differently.

Answer 2

happened same with me. When I installed tensorflowjs, it downgraded my prompt-toolkit version to 1.0.14. To solve this issue just upgrade prompt-toolkit version to 3.0.5 by running the following code in your command prompt:

 pip install prompt-toolkit==3.0.5