Hi Dave,

From that error it looks like there’s some issue in saving the generated figure into an image file. Have you already had a viz folder in the same path as the notebook file (if you clone my entire repo you should have it)? If not, perhaps you can create a viz folder or modify the path with fig.savefig(<path of your choice>/weight.png. I think it should work after that, but please let me know if it doesn’t.