After upgrading to 5.9.x, custom language pack used for Code Block Macro has stopped working

Steps to Reproduce

1. Upload custom language pack: abaphighlighter into your Confluence Admin > Configure Code Macro: Add a new language.
2. Optional: Set your Confluence Default Language to the custom language pack.
3. On a Page, insert Code Block Macro with the following parameters:

• Syntax Highlighting: abaphighlighter
• Theme: FadeToGrey

4. Click on Save to insert the Code Block Macro into the Page.
5. Put in a Sample Code (refer to Testing Notes)

Expected Result:

• Code Block Macro should show the correct Theme and Syntax Highlighting as per the custom language pack

Actual Result:

• Code Block Macro showing no Theme and no custom Syntax Highlighting as per the custom language pack

Additional Notes:

• Screenshots attached for Testing Results
• Custom Language pack attached

WorkAround

Manually downgrade the Code Block Macro plugin to version 2.1.7.

To downgrade the add-on, do the following:

1. Stop Confluence.
2. Locate the existing .jar files (newcode-macro-plugin-XXX.jar) in <confluence-install>/confluence/WEB-INF/atlassian-bundled-plugins/. Move the file to a different location to create a backup copy.
3. Place the attached, newcode-macro-plugin-2.1.7.jar , into the atlassian-bundled-plugins directory.
4. Locate the existing transformed .jar (newcode-macro-plugin-XXX_XXX) in <confluence-install>/plugins-osgi-cache/transformed-plugins/.Delete the file.
5. Start Confluence.

As with all recommendations, we strongly suggest testing this in a test environment prior to implementing in Production. If this causes other issues in your instance, you will be asked to switch back to the original version of the .jar.