In this post Please note: use files.fast.ai, not platform.ai, from now on @jeremy asked folks to use files.fast.ai moving forward.
I recommend going into the vgg16.py file and updating the paths in there.
Personally I also changed the cache directory to not be in the hidden .keras folder by default. I created a folder in my user directory and changed all the cache="models" to be cach="~/models" That way I can see what I’ve cached and/or downloaded.