Cannot validate "Optimizing KMeans algorithm" in "Community Detection with GDS" course

The quiz of the page "Optimizing KMeans algorithm" in "Community Detection with GDS" course seems to be broken with the error:

"Unresolved directive in lesson.adoc - include::questions/1-metrics.adoc[leveloffset=+1] :leveloffset: +1"

And so, even if I respond with the correct answer, it doesn't validate it and so I cannot finish the course.

Thanks