Page not found yet the posts are listed?

It’s not correct solving of issue and it’s not a bug. Here is explanation why it happens: “Pagination is calculated before you get to the template file that runs query_posts. The proper way to alter posts_per_page conditionally is to use the pre_get_posts hook to modify the main query.”
https://wordpress.stackexchange.com/a/42063/17177
I found one implementation “pre_get_posts” that works for me http://uncommoncontent.com/2012/01/28/add-custom-post-types-to-the-loop:

if ( ! function_exists( 'ucc_add_cpts_to_pre_get_posts' ) ) {
    function ucc_add_cpts_to_pre_get_posts( $query ) {
        if ( $query->is_main_query() && ! is_post_type_archive() && ! is_singular() && ! is_404() ) {
        $my_post_type = get_query_var( 'post_type' );
            if ( empty( $my_post_type ) ) {
                $args = array(
                    'exclude_from_search' => false,
                    'public' => true,
                    '_builtin' => false
                );
                $output="names";
                $operator="and";
                $post_types = get_post_types( $args, $output, $operator );

                // Or uncomment and edit to explicitly state which post types you want.
                // $post_types = array( 'event', 'location' );
                // Add 'link' and/or 'page' to array() if you want these included.
                // array( 'post', 'link', 'page' ), etc.
                $post_types = array_merge( $post_types, array( 'post' ) );
                $query->set('post_type', $post_types );
            }
        }
    } 
}

add_action( 'pre_get_posts', 'ucc_add_cpts_to_pre_get_posts' );