Failed to extract shortcode

I realise that I have not given enough information. I am just trying to get the Academic theme for Hugo up and running. I closely follow the instructions (https://sourcethemes.com/academic/docs/install/) and get the following error when I click on “build” in Rstudio:
Error: Error building site: “/Users/gattuso/not_synced/web_site/content/slides/example-slides.md:75:5”: failed to extract shortcode: template for shortcode “fragment” not found

Thanks