Can't create ipyparallel clusters on Jupyter Notebook - jupyter-notebook

Question

I have the following:
ipyparallel (5.0.0)
ipython (4.0.3)
I have enabled ipcluster by typing in the command line:
ipcluster nbextension enable
I'm trying to create a new cluster on the IPython Clusters tab on the Jupyter notebook, but this is what I see:
I was able to do this before. Thanks!

Answer 1

From here:
Instead of editing jupyter_notebook_config.py, edit jupyter_notebook_config.json and look for:
"NotebookApp": {
"server_extensions": [
<some lines>
]
change this to:
"NotebookApp": {
"server_extensions": [
<some lines>,
"ipyparallel.nbextension"
]

Answer 2

I've just stumbled upon the same problem, and the fix mentioned in the accepted answer worked, but let me add some context for the future visitors of this question, just in case.
I have Anaconda 5.0 for Linux, under that I first did:
jupyter notebook --generate-config
pip install ipyparallel
jupyter nbextension install --py ipyparallel --user
jupyter nbextension enable --py ipyparallel --user
jupyter serverextension enable --py ipyparallel --user
Which lead to the situation on the screenshot.
Under ~/.jupyter I have both jupyter_notebook_config.json as well as jupyter_notebook_config.py.
The json file had this inside:
{
"NotebookApp": {
"nbserver_extensions": {
"ipyparallel.nbextension": true
}
}
}
I changed the file by adding a "server_extensions" block as follows:
{
"NotebookApp": {
"nbserver_extensions": {
"ipyparallel.nbextension": true
},
"server_extensions": [
"ipyparallel.nbextension"
]
}
}
After restart, Jupyter reported in the logs:
[W 19:44:14.107 NotebookApp] server_extensions is deprecated, use nbserver_extensions
However, the Clusters tab started working as necessary. Apparently, some recent changes in the configuration logic did not propagate to all of the codebase.