Fixed it by downloading the latest fastai source from github again, deleting my existing folder (which I had called “fastai2”, btw) and extracting the github .zip to “fastai-master” and then renaming that new folder to be just “fastai”. Started my kernel again, and all fixed now.
Note that I had followed the steps written in Deploy fastai-v2 model on windows machine in the meantime, gotten the “No module named ‘fastai2’” error mentioned on that page and then updated my fastai source, but I then went back and tried the environment and kernel I already had when I was getting the error on this page, and it’s still fixed, so I think the issue is simply using a version of fastai with a bug in…