PSA for those completing the Data Visualization Course

Hi, guys! I wanted to make everyone aware of a small issue I realized today. I have been working all day on my Data Visualization projects on CodePen, with each failing at the very end and giving this same kind of error:

TypeError: d.geometry is undefined
TypeError: d[0] is undefined

I spent hours editing and changing things, googling, looking through this forum, asking friends for feedback on the code, etc. No one could find the issue. As a last ditch effort I changed the external script from:

/ajax/libs/d3/7.8.0/d3.min.js (the one CodePen auto-loads after you type “d3”)

to

/ajax/libs/d3/5.15.0/d3.min.js

and suddenly all tests on all projects are passing. I honestly don’t know how this was breaking the codes, but I am so glad that I finally found the problem. I hope this can help others out!