Hi, When i enable most comments fresh stat will get query error, no comments table and c.timestamp column, at mostpopular_drupal.module line
112: 

$query->innerJoin('comments', 'c', 'n.nid = c.nid');

117: 

 ->condition('c.timestamp', $ts, '>=')

should be change to like this, 

$query->innerJoin('comment', 'c', 'n.nid = c.nid');
->condition('c.created', $ts, '>=')