Hi Graham,
Thank you! for checking this.
Here below is what I did for Mastery Paths,
1.I did enabled this Mastery Paths feature from account and course.
2.While enabling I got error saying consul.yml is not present so I created that config file ( There I have mentioned the host of the same Canvas instance with other port.)
3.Now Its started showed the mastery path menus in the assignment,discussion and wiki page.
4.But when I click the Mastery Path tab its giving error saying mastery path editor is not configured.
So I started debugging this and I found below things,
a.In canvas only the skeleton to bring the Menu and API logic for storing and retrieving data only there (Please refer app/models/conditional_release/service.rb).
b.There is a separate service which is providing data and JS for managing the mastery path content (Please refer screenshot those routes/path not available in
the open source version)
Did you managed enabled Mastery Path and is it working on your version?