Popular Post With Thumbnail?

If you know the $Post->ID of the “most popular post”, why not just use get_the_post_thumbnail() (Codex ref):

<?php echo get_the_post_thumbnail( $id, $size ); ?>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)