Pagination error

Hi , i’m having some trouble with pagination.
In search.php , i call the function for paging (the default one), the first page result all ok, the 2-3….. pages show me error (saying the page does not exist)

The link generated is the following

http://mysite.com/?search-class=DB_CustomSearch_Widget-db_customsearch_widget&widget_number=preset-default&cs-post_title-0&search=Search&paged=2

Where is the problem ?

thanks in advance

https://ww.wp.xz.cn/plugins/wp-custom-fields-search/