If you receive an error similiar to "Use of undefined constant LANG_CHAT_.. - assumed 'LANG_CHAT_.." or "Update language pack", it is due to the custom language file that has been created and the latest build of PHP Live! is not able to retrieve the proper variables from the custom language file.
- Copy an existing language file from the phplive/lang_packs/ directory and rename the copied language file to a new name and proceed to edit the file to your needs.
- Update your language settings at the PHP Live! setup->Settings to use the new language file containing the proper format.