OM Extension -Help required

Summary:

We are trying to set the trxtype at line level using OM extension but are facing an issue.

Content (required):

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

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

List<Message> msgs = new ArrayList<Message>();

Message msg;

def billingTxnTypeId = null;

def lines = header.getAttribute("Lines"); 

while( lines.hasNext() ) {                  

def line = lines.next();  

def flexfieldContextLine = line.getOrCreateContextRow("Additional Line Information");               

def EFFLine = flexfieldContextLine.getAttribute("department"); 

  TransactionLineTypeCode = line.getAttribute("TransactionCategoryCode");

  

  if((TransactionLineTypeCode == "ORDER"))

 {

  billingTxnTypeId = getBillingTxnTypeId("100 INVOICE");

}}

error message :

An error occurred when running extension AR transaction, during event On Save: oracle.jbo.JboException: JBO-29000: Unexpected exception caught: groovy.lang.MissingPropertyException, msg=No such property: messages for class: ExID300000007677733__25. (DOO-2685874)