Hi,
We updated the documentation of the "attach serial" plugin in order to fix a recurrent problem about the sample image.
You have to be sure that is a good working image file named "coupon_01.png" in your "images" folder.
Or you can try to use the new image that we include directly in the HikaSerial package : /media/com_hikaserial/images/coupon_01.png
www.hikashop.com/support.html?id=152:hik...ns-attachserial-form
If with the new sample you can't even make it work, you can send me a backend access to your website (by private message) and I will check and fix your configuration.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.