Database error: Got error 28 from storage engine
Query:
SELECT `S`.`id`, `S`.`parent`, `S`.`code`, `S`.`name`, `S`.`website_id`,
 `T`.*,
 COUNT(CMT.id) AS `count_comments` 

 FROM `structure` AS `S`
INNER JOIN `material` AS `T` 
	ON S.id = T.id
LEFT JOIN `comment` AS `CMT` 
	ON CMT.entity_id = T.id AND CMT.creation_date < 1497407682
WHERE `S`.`visibility` NOT IN ('1', '4') AND `T`.`creation_date` < '1497407682'
GROUP BY `T`.`id`
ORDER BY `T`.`creation_date` DESC