Hi,
HikaShop process some SQL queries during the update and I think that it add some troubles (maybe not the right to alter tables ?).
I don't know from which version you have updated but you can find the different SQL queries for the updates in the "install.hikashop.php" file.
For the update from HikaShop 2.2.3 to HikaShop 2.3.0, theses queries are processed:
ALTER TABLE `#__hikashop_taxation`
ADD `taxation_date_start` int(10) unsigned NOT NULL DEFAULT '0',
ADD `taxation_date_end` int(10) unsigned NOT NULL DEFAULT '0';
CREATE TABLE IF NOT EXISTS `#__hikashop_warehouse` (
`warehouse_id` INT(10) NOT NULL AUTO_INCREMENT,
`warehouse_name` VARCHAR(255) NOT NULL DEFAULT '',
`warehouse_published` tinyint(4) NOT NULL DEFAULT '1',
`warehouse_description` TEXT NOT NULL,
`warehouse_ordering` INT(10) NOT NULL DEFAULT 0,
`warehouse_created` int(10) DEFAULT NULL,
`warehouse_modified` int(10) DEFAULT NULL,
PRIMARY KEY (`warehouse_id`)
) ENGINE=MyISAM;
ALTER TABLE `#__hikashop_product` ADD `product_warehouse_id` int(10) unsigned NOT NULL DEFAULT '0';
Where you have to replace "#_" by your database prefix.
Example: if your database joomla prefix is "jos", the table "#__hikashop_taxation" will become "jos_hikashop_taxation".
Regards,