Summary

The documentation for the Code Block Macro mentions that additional languages can be added if they adhere to the custom brush syntax for Syntax Highlighter. However the brushes built from the newest version (v4) are not accepted by Confluence.

Steps to reproduce

1. Follow the build steps in Syntax Highlighter to output a brush
2. Attempt to upload the brush into Confluence via Confluence Admin > Configure Code Macro

Expected behavior

A green box stating: "Successfully added the language".

Actual behavior

A red box stating: "The uploaded language file is not a valid language definition. Consult the application log for further information."
(Note that nothing is actually logged in the application logs.)

Other notes

SyntaxHighlighter v3 versions of the brushes seem to work in Confluence, while v4 does not. Details between the two can be found: https://github.com/syntaxhighlighter/syntaxhighlighter/wiki/Migration-Guide