Trying to add a test card number in the sandbox env

[paries]

I am trying to test my flow with a new integration.

I have created a test user in www.sandbox.paypal.com

But I can not successfully link a card.

I have tried using cards from 
https://developer.paypal.com/api/nvp-soap/payflow/integration-guide/test-transactions/#processor-is-...

Thanks for any help

Every card i try i get the error 
"Check your information and try again"