Extra code causing display issues?

-- HikaShop version -- : 2.4.0
-- Joomla version -- : 2.5.28
-- Browser(s) name and version -- : chrome

Hi
on all of our shop pages there is an extra "-->" displaying at the top of the page, along with a block of hidden code framed with "for reference"

For some pages, this appears to be throwing off the page display and duplicating content
www.thehow2doc.com.php53-18.ord1-1.websi...-2/category/19-games
www.thehow2doc.com.php53-18.ord1-1.websi.../category/12-writing

I have been unable to locate where to remove the extra close code, and can't figure out how to turn off the duplicate content - is this necessary? can it be turned off somewhere?

new to HikaShop and trying to get something to work after trying other carts for our client.
We are using the starter version
Thank you

Follow up - the extra code is on all the pages, so it's not Hika-related.
I still need to know how to remove what appears to be duplicate content on some of our pages.

Thanks!!!!