prepare エラー　タグ一覧表記　

http://nendeb.jp/?p=563

http://cathval.com/wordpress/3107

とりあえず

prepare("SQL文");
を
prepare("SQL文",null);

で対応

//Twenty Fourteen: サイドバー (sidebar.php)   
<div id="secondary">
//ここから
          <ul> 
           <li>タグ</li>
         <?php
$tagList = $wpdb->get_results($wpdb->prepare("
    SELECT t.term_id,t.name,t.slug,tt.count
    FROM $wpdb->terms AS t
    JOIN $wpdb->term_taxonomy AS tt
    USING(term_id)
    WHERE tt.taxonomy = 'post_tag'
    ORDER BY tt.count DESC
",null));
foreach ($tagList as $value):?>
<?php
$add_style = '';
$add_class = '';
if( is_tag( $value ) ){
	$add_class = 'current';
	$add_style = 'style="color:#71B6FC;"';
}
?>

<li>
<a href="/?tag=<?php echo $value->slug; ?>/" <?php echo $add_style;?> class="<?php echo $add_class;?>">
<?php echo $value->name; ?></a> 
(<?php echo $value->count; ?>)</li>
<?php endforeach;?>
         </ul>