Hi, I purchased minimal theme. But I got rss problem, it dont work. I try to fix it but I didnt…

Warning: require_once(/home/mustesna/public_html/wp-includes/feed-rss2.php) [function.require-once]: failed to open stream: No such file or directory in /home/mustesna/public_html/wp-includes/theme.php on line 1112

Fatal error: require_once() [function.require]: Failed opening required '/home/mustesna/public_html/wp-includes/feed-rss2.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/mustesna/public_html/wp-includes/theme.php on line 1112

Help me pls.