Order Validation fails with an error

Summary:

We are trying to populate the Sales credits attribute value using Order management Extension code. But it got failed with the error message "You must enter a value for the Original System Sales Credit Reference attribute." once we clicked the submit button. Same sales credits value processed successfully if we pass it manually. Groovy Script code attached for your reference. Could you please help us to fix this?

Content (please ensure you mask any confidential information):

import oracle.apps.scm.doo.common.extensions.ValidationException;

import oracle.apps.scm.doo.common.extensions.Message;

def SalesCredits = header.getAttribute("SalesCredits");

def sc= SalesCredits.createRow();