Как исправить запрос в модуле EnePM?

MySQL error in file: \engine\modules\ene_pm\ene_pm.php at line 97
Error Number: 1055
The Error returned was:
Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'shnyagi_net.e.from_user_id' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by
SQL query:

SELECT e.from_user_id, e.user_id as uid, u.user_id as userid, u.name, u.fullname, u.foto, u.lastdate FROM dle_ene_pm as e, dle_users as u WHERE (e.from_user_id=u.user_id AND e.user_id='34') OR (e.user_id=u.user_id AND e.from_user_id='34') GROUP BY userid ORDER BY `date` DESC LIMIT 6

$sql_getlastuser = $db->query("SELECT e.from_user_id, e.user_id as uid, u.user_id as userid, u.name, u.fullname, u.foto, u.lastdate FROM " . PREFIX . "_ene_pm as e, " . PREFIX . "_users as u  WHERE (e.from_user_id=u.user_id AND e.user_id='{$member_id[user_id]}') OR (e.user_id=u.user_id AND e.from_user_id='{$member_id[user_id]}') GROUP BY userid ORDER BY `date` DESC LIMIT $select");