Get a line like [<matplotlib.lines.Line2D at 0x7f610447e140>] when trying to plot, and an 'empty' plot which seems to have a toolbar of button, but no content. Failed to fetch ipywidgets through the ...

Ipympl (which is awesome) regularly breaks with minor matplotlib version updates. This typically causes a cryptic 'javascript error' in the jupyter notebook. Here is the output from the latest ipympl ...