OLD PS 1.5 - Issue with homepage

[ZioFranky]

Hello to everyone. Hope somebody can help me.

Website worked fine for many years without no problem. I tried to lighten the DB removing stored stats and datas (slowing down performances) using the PSCLEANER module. Probably a bad move.

Every single page of the website works fine, except the homepage that shows only the header and the footer. No modules seem to be linked to home hook.

Turning on the error reporting i get this error:

Fatal error: Uncaught 'psdbname.hm.position' isn't in GROUP BY<br /><br /><pre>SELECT h.`name` as hook, m.`id_module`, h.`id_hook`, m.`name` as module, h.`live_edit` FROM `ps_module` m INNER JOIN `ps_hook_module` hm ON hm.`id_module` = m.`id_module` INNER JOIN `ps_hook` h ON hm.`id_hook` = h.`id_hook` LEFT JOIN `ps_module_group` `mg` ON mg.`id_module` = m.`id_module` WHERE ((SELECT COUNT(*) FROM ps_module_shop ms WHERE ms.id_module = m.id_module AND ms.id_shop IN (1)) = 1) AND (h.name != "displayPayment") AND (hm.id_shop = 1) AND (mg.id_shop = 1 AND mg.`id_group` IN (1)) GROUP BY hm.id_hook, hm.id_module ORDER BY hm.`position` </pre> thrown in /public_html/classes/db/Db.php on line 613

Is there any way to fix this?