Hi,
Extract the HikaShop install package and change the code:
$query = 'UPDATE `#__hikashop_user` AS hku JOIN `#__users` AS ju ON hku.`user_email`=ju.`email` SET hku.`user_cms_id`=ju.`id` WHERE hku.`user_cms_id`!=ju.`id`';
$this->db->setQuery($query);
$this->db->query();
to:
$query = 'UPDATE `#__hikashop_user` AS hku JOIN `#__users` AS ju ON hku.`user_email`=ju.`email` SET hku.`user_cms_id`=ju.`id` WHERE hku.`user_cms_id`!=ju.`id`';
$this->db->setQuery($query);
try{$this->db->query();}catch(Exception $e){}
in the file back/helpers/update.php, then compress again the files into a zip and use that zip for the install and that should hopefully avoid the problem. If not, simply delete these lines from that file all together and it will work.