Issue with '/' or '#' in notebook URL
It seems there is an issue that may be related to issue #665 because the branch name also contains a slash. However, the quick fix mentioned in that issue to percent-escape the slash to %2F does not work in my case.
The notebook URL that fails with 404 is:
https://raw.githubusercontent.com/pywbem/pywbem/ks/%23682new-notebooks/docs/notebooks/connections.ipynb
The Git branch name is ks/#682new-notebooks. As you can see, the hash sign is percent-escaped in the URL but the slash is not. I got this URL from the raw representation of the file in Github, and it does resolve in a browser, so from a perspective of the GitHub site it must make some sense to escape the hash but not the slash.
I would expect that NBViewer can deal with all URLs that resolve.
I should add that I used the http://nbviewer.jupyter.org site to view the notebook, where it failed with 404, both with the URL as shown above, and with the branch slash escaped.
Andy
I have the same issue. Substituting the forward slash in the branch name with %2F will allow nbviewer to navigate to the correct branch but it still fails to open and render the notebook.