Answer by Golu for Wordpress post category out of the loop but in the rss feed

You need to exclude the feed (edit page templates also) page from your if condition

function excludeCat($query){    if ($query->is_home() && !is_page()) {        $query->set('cat', '-14, -64, -68, -22, -15');    }    return $query;}add_filter('pre_get_posts', 'excludeCat');

Edit

Add this before the line number '5' IE before the line with $postCount = 10; , in rss-ppfeed.php

remove_filter('pre_get_posts','excludeCat');