PDF invoice plugin mass invoices export

-- HikaShop version -- : 2.6.0
-- Joomla version -- : 3.4.5
-- PHP version -- : 5.5.30

Hi,

I'm trying to export all invoices by selecting all shipped orders in orders page and clicking invoice button on the top but I receive this error:
Fatal error: Call to undefined method hikashopProductClass::loadFullOrder() in /site_root/plugins/hikashop/attachinvoice/attachinvoice.php on line 34

With your plugin I just edited this file: /site_root/plugins/hikashop/attachinvoice/attachinvoice/invoice.php to change layout.
If I select only one order from the list I'm able to download invoice without problem. If I select two or more orders I recieve the fatal error.

What should I do to download all invoices?

Thank you,
S

Thank you for your quickly reply, I went to my order details page to download the updated plugin but I'm not able to do it. There is written "PDF Invoice plugin install package Download period has elapsed".

Do I have to buy it again? What about my custom layout, do I have to copy/paste the code when I'll install the plugin?

Thank you,

superb support!