Chapter 2 of the online version of this book has an issue with the URL for the official D3 website. It is listed as http://www.d3js.org/, which will result in an error if visited, rather than https://d3js.org/, which is the correct URL.
The page in question is https://learning.oreilly.com/library/view/interactive-data-visualization/9781491921296/ch02.html.
Not sure if this is something that has to be corrected by O'Reiley