ipython: Notebook does not appear to be JSON

The problem for me was that I had an unresolved merge conflict in my ipython notebook. So I opened the file and deleted one version (HEAD>>>>> and what came after it up until ======= and then the line containing <<<<<<). In short, resolve the merge conflict and you'll be good.

I've faced similar problem when I'm using IPython notebook (Jupyter) for H2O. I installed Anaconda Ver 3.X and when i did with Anaconda 2.7.9 it worked without the JSON error. It's because IPython (Jupyter) doesn't yet support for Version 3.X of Anaconda (Python)