Problem paypal Express Checkout Sandbox : Error 12203

Hi ! I need you're help, again.

I have a Paypal error when I try to configure my Paypal Epress Checkout with global cart enable on a Multisite :
12203 - Instant payment required for 3pxo. - Instant Payment in 3PXO cannot be pending. The transaction has been rolled back.

I read on the Internet :

Payment was not created because it would have been in a pending state, which is unacceptable for Immediate Payment items. Check your API requests for the SetExpressCheckout and DoExpressCheckoutPayment to see if you are passing over one of the following variables and setting it to "InstantPaymentOnly".
PAYMENTREQUEST_n_ALLOWEDPAYMENTMETHOD
ALLOWEDPAYMENTMETHOD
If you are this would be the cause of your error. If you are not wanting to accept instant payments only, you can remove this variable.

So, I have to change the code or a parameter in the administration ? Or is it something in Paypal ?

Sincerly,