In my shop(prestashop 1.5.3.1) some times invoices are generated with wrong data. Price is different from actually billed price. There is no product info(name,unit price etc) displayed on such bills. As you can see on my screenshots the tax and price values are incorrect on the invoice. Any hint about this?
Update 1:
The error only happens when purchasing products that have no combinations with epay checkout module.
update 2:
I think the error is with epay module. Issue with invoice generation is gone when I disable epay invoicing(invoice generated on epay server). Even though I can see an error: "Notice: Undefined index: attributes_small in /modules/epay/epay.php on line 458" when prestashop development mode is true.