The name is familiar, helas the soft is somewhat older. Likely cause will be the 'age' in coding depending the connections to admin/user.
This would need a re-write of some of the parts that communicate/uses the settings for admin and users. That it does not work is for me the 'proof' that it does not know what to do, or misfired some rules that interfere..
If you want the site to run again, delete or rename the components for chat, and/or change setting in database concerning the chat (or zip contents). (always backup of course).
Both are for me unknown cq never used.