Can not delete attachments

Users/admins are unable to delete attachments from the product screen:

User can not delete a products attachment from with in the product screen.
This happens on our live sites but also in the Attachment Plugin demo site:
http://admin-demos.nop-templates.com/Admin/Product/Edit/19

Using the delete button to remove an attachment pops up "Are you sure you want to delete this item?"
Hitting ok yields no result.

Similarly after creating a new attachment and hitting save, the popup window does not close, it just loads a blank screen.

DevTools failed to load source map: Could not load content for http://admin-demos.nop-templates.com/lib_npm/fine-uploader/jquery.fine-uploader/jquery.fine-uploader.min.js.map: HTTP error: status code 404, net::ERR_HTTP_RESPONSE_CODE_FAILURE

Looks like this is an external plugin, Try contacting the vendor for support as you don't have access to the source.

It was my understanding this is a plugin provided by nop

nop-templates.com is a 3rd party  (I.e., They are not nopCommerce.com)