Uncaught RuntimeError: asciidoctor: FAILED: missing converter for backend 'deckjs'. Processing aborted.HubPress supports the HTML5 back-end. Specifying other back-end types in your blog posts results in an error like:
Uncaught RuntimeError: asciidoctor: FAILED: missing converter for backend 'deckjs'. Processing aborted.To use a different backend to process your AsciiDoc files, see the Asciidoctor User Guide
The Selecting an Output Format section in the User Guide can help you work out the backend that is right for you, for use with the asciidoctor command-line script.