How to reply to comments in a comments list
Using Jamroom
The reason is that when you make a list of comments, there is not going to be a comment form there unless you put one there.
The REPLY button is expecting you to have put a comment reply form in there somewhere so the user can reply.
is what the javascript on the REPLY button is searching for. You can see the rest of the form in the jrComment/template/comment_form.tpl template.
If you're wanting to remove the reply button, i'd suggest CSS. If you're wanting to add the comment form too, it might be doable with a TEMPLATE CODE widget and site builder.