In WordPress, Custom Post Type is great feature to manage your custom content such as portfolio which can’t be managed properly with the default posts or pages type.
One of the problem in working with custom post types is the pagination issue. If you are viewing the same records on the next or third page of listing, you need to catch $paged variable and pass to the query like this:
//your html code here
Sorry, no record matched your criteria.
Hope that helps.