Altair not rendering in Jupyter notebook

Hi there,

I’m running into an issue that popped out seemingly out of no where. As of this morning, when I try to run a simple Altair plot, it fails to render in the jupyter notebook. Like:

import pandas as pd
import altair as alt
df = pd.DataFrame(dict(a=[1], b=[2]))
alt.Chart(df).mark_point().encode(x='a', y='b')

which yields:

Error loading script: Script error for "vega-util", needed by: vega-embed http://requirejs.org/docs/errors.html#scripterror

In the command line of the notebook, I also see:

 404 GET /static/vega-util.js?v=20200908081432 (::1) 2.82ms referer=http://localhost:8888/notebooks/bug_demo.ipynb

I’m running on Windows 10, which may have updated itself last night. I’m at a loss. I’ve tried a few things: uninstalling/install jupyter, notebook, altair and vega, but none of that seems to work. Any help would be huge!

[domoritz]

Hmm, it looks like the browser is trying to load vega-util from /static but it’s not there. I can probably make a change to Embed to load vega instead.

[domoritz]

I’m fixing it. Please follow https://github.com/vega/vega-embed/issues/557.