Hi,
You should have started with that and told us that you're not using the plugin file from the latest version of HikaShop but this one:
www.hikashop.com/media/kunena/attachments/5807/authorize.txt
(if I understand correctly)
As you can see on this file, you don't have the line I talked about in my previous message:
$vars["x_line_item"][]=substr($product->order_product_code,0,30).'<|>'.substr(strip_tags($product->order_product_name),0,30).'<|>'.substr(strip_tags($product->order_product_name),0,30).'<|>'.$product->order_product_quantity.'<|>'.round($product->order_product_price,(int)$this->currency->currency_locale['int_frac_digits']).'<|>'.$has_tax;
Instead, you have the code:
$vars["x_line_item"][]=substr($product->order_product_code,0,30).'<|>'.substr(strip_tags($product->order_product_name),0,30).'<|><|>'.$product->order_product_quantity.'<|>'.sprintf("%01.2f", round($product->order_product_price,(int)$this->currency->currency_locale['int_frac_digits'])).'<|>'.$has_tax;
So please try with the line from the current version of HikaShop.
That might help.
Otherwise, a backend access and a FTP access would be necessary for us to understand the issue.