Hide Category from Blog?

You want the category 98 to be excluded only on the blog page, right? They should be accessible on the category page directly (your downloads page), correct?

Can you try this? Let me know if its not what you want, we can modify it to suit your needs. Right not it only excludes the category on where you show your blog posts.

add_action('pre_get_posts', 'block_cat_query' );

function block_cat_query() {
    global $wp_query;   
    if( is_home() ) {
        $wp_query->query_vars['cat'] = '-98';
    }
}