I am also having the same issue. It is with the setting of the theme. At the proper section of the tutorial I had chosen the Minimal theme. Then later, the course asked me to change that in the _yml file to …
I think this is a fluke in the course. I have a hunch that it wanted us to instead choose
which is what I already had it set to, but that is not the instructions given to us in the coursework.
Initially I had left it that way, but it showed an error because I had not changed it. Then when I changed it to match info on the PDF of the course, it continued with the error that previous people reported.