Cannot get a comments form

I downloaded the theme “Desk Mess” and installed it. I cannot seem to get the comments working. There is no form that comes up but only the error:Not Found
Sorry, but you are looking for something that isn’t here”

I written to the Author of the theme but have received no response. I am less than a rookie at this but follow instructions well. I am using cPanel for editing and admin. I thought about copying and pasting files from one of the other themes (classic or default) but don’t know which ones to copy.