Paypal sandbox msg "this invoice has been paid"

Hi,
I'm testing the payment with paypal default plugin.

After a failure, I place everytime a new order (new order number too). At the end of paiment attempt on paypal sandbox website I get the following error "This invoice has been already paid. Please contact the merchant".

Obviously, as I made a new order each time, it is not possible it is already paid.

I've even changed the invoice format, adding letters, and logout login, but I get always the same alert message.

Any hint?
Thanks in advance

Hi,

That means that the paypal account was already used before by another ecommerce solution which already used up these numbers.
I invite you to follow our documentation on that error:
www.hikashop.com/support/documentation/i...l-error.html#already

Hi Nicolas,
thanks for your help.
I haven't such of that block config in sandbox account, anyway altering the autonumber solved my prblem.

Thanks you.