Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Go to Administration > General Configuration > Configure Code Macro
2. Choose Add a new language.
3. Locate your language file and enter a Name for the new language (this will appear when selecting the language).
4. Choose Add.

Language files must be correctly formatted JavaScript files and adhere to the Custom Brush syntax. You can see examples in <install-directory>/confluence/includes/js/third-party

Alternatively, use the attached example file to upload

Expected Results

1. the file should get uploaded without errors
2. the new language should be available in Code Macro

Actual Results

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available