Spyder could not get alist of sessions from the Jupyter Notebook server

[gker]

I'm getting the following message when using Jupyter notebook in Spyder:

I'm running the latest anaconda and spyder packages in Windows 10.

[Radoslaw Przysowa]

In the past spyder-notebook worked only with an external notebook server. You had to start jupyter-notebook externally and use http://localhost:8888/ in spyder-notebook 

In the recent version 0.2.3, there is the internal jupyter server in Spyder. It is better integrated and you can open its console and inspect variables. When you launch jupyter-notebook in the background, it gets 8889 address after the server built in Spyder.

However, spyder jupyter server does not work in all my anaconda installations in Windows. Sometimes resetting Spyder to factory defaults helps. There is no documentation for this built-in spyder-notebook server while the source code is not clear to me.

I hope somebody could explain this confusing behaviour.