I am trying to write a scheduled script to run each night. It will take any Transfer Orders that are NOT received in NetSuite but ARE received in Amazon and receive each line item. My code is as follows:

/**
 * @NApiVersion 2.x
 * @NScriptType ScheduledScript
 */
 define(['N/search','N/record'], function (s,r) {
	function execute(context) {
      var approvalSearch = s.load({
        id: 'customsearch_to_tbreceived'
      });
      var resultSet = approvalSearch.run();
      resultSet.each(processTransferOrder);
	};

	function processTransferOrder(result){
		var internalID = result.getValue(result.columns[0]);
      	log.debug({title:'InternalID',details:internalID});
      	var record = r.load({
			type:'transferorder',
			id:internalID
		});

      	var irRecord = r.transform({
          fromType: 'transferorder',
          fromId: internalID,
          toType: 'itemreceipt'
        });

      	var itemCount = irRecord.getLineCount('item');

      	for (var i = 0; i < itemCount; i++){
          var itemId = irRecord.getSublistValue('item','item',i);
          var quantity = irRecord.getSublistValue('item','quantity',i);
          var lineId = irRecord.getSublistValue('item','line',i);
          var location = irRecord.getSublistValue('item','location',i);
          log.debug({
            title:'Item - Quantity - LineId - Location',
            details:itemId + ' - ' + quantity + ' - ' + lineId + ' - ' + location
          });
          irRecord.setSublistValue({
            sublistId: 'item',
            fieldId: 'itemreceive',
            line: lineId,
            value:true
          });
        }

      	var idl = irRecord.save({
          enableSourcing: true
        });
        return true;
	};
	return({
		execute:execute
	});
 });

When it runs, it gives the following error:

{
  "type": "error.SuiteScriptError",
  "name": "UNEXPECTED_ERROR",
  "message": null,
  "stack": [
    "anonymous(N/serverRecordService)",
    "processTransferOrder(/SuiteScripts/bb_auto_receive_to.js:39)",
    "each(N/searchObject)",
    "execute(/SuiteScripts/bb_auto_receive_to.js:11)"
  ],
  "cause": {
    "type": "internal error",
    "code": "UNEXPECTED_ERROR",
    "details": null,
    "userEvent": null,
    "stackTrace": [
      "anonymous(N/serverRecordService)",
      "processTransferOrder(/SuiteScripts/bb_auto_receive_to.js:39)",
      "each(N/searchObject)",
      "execute(/SuiteScripts/bb_auto_receive_to.js:11)"
    ],
    "notifyOff": false
  },
  "id": "853f25fd-e6ab-452a-9ffb-13ced90c4b5c-2d323032322e30362e3238",
  "notifyOff": false,
  "userFacing": false
}

It gives this error on line 39 on the 2nd iteration through the items. Anyone see what I am doing wrong?

its not required for the line id to be the same as the line number

Should 'line' always be equal to 'i'?

yes

Thanks, testing now