Paypal error 10413 after discount

[delsang]

Hi everyone!

 

I have a buy 5+ items, get a 20% discount on some of my products on my website and when the customers use the voucher they get an error 10413 from paypal.

 

I've looked around the forum but still don't know what to do...?

 

Few infos:

- no shipping fees are charged

- no taxes are charged 

- Version of prestashop : 1.6.0.6

- version of paypal module : 1.3.8

 

the website is http://www.ethicalbazaar.com and the discount is on the Christmas items.

 

Let me know if you need more infos,

 

Cheers,

 

Delphine