Responsive Shop Theme My SQL Error

Do anyone know what this is:

[27-Dec-2013 07:48:12 America/New_York] WordPress database error Unknown column ‘ert4_postmeta.meta_value’ in ‘order clause’ for query SELECT SQL_CALC_FOUND_ROWS DISTINCT ert4_posts.ID FROM ert4_posts WHERE 1=1 AND ert4_posts.post_type = ‘post’ AND (ert4_posts.post_status = ‘publish’) ORDER BY ert4_postmeta.meta_value+0 desc LIMIT 0, 12 made by require(‘wp-blog-header.php’), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts