First.Last to DN Workflow

Question

We've got Okta pushing manager first.last to extensionAttribute3 in ARS. I need a workflow that will convert that to a DN to drop into the manager field. However, no matter what I do, it doesn't want to get from any attributes. Workflow setup: On Demand EA3 Search - Filters from an OU with 4 users. No other filters in place. --> Run Script: First.Last to DN 
 First.Last to DN script 
 function onPostModify($Request)
{
$sourceObj = $workflow.FoundObject("EA3").get("DN")
$manager = get-aduser -identity $sourceObj -properties extensionattribute3 | select -expandproperty extensionattribute3
$managerDN = (get-aduser -id $manager).distinguishedname	
$dirobj.put("manager", $managerDN)
$DirObj.SetInfo()
} 
 The error I get when I try to run the workflow with the script is:

At line: 3 char:1. Exception calling "Get" with "1" argument(s): "Object reference not set to an instance of an object."

Terrance.Crombie · Answer

The error message is on line 3, where you are calling the workflow.FoundObject("EA3").get("DN") 
 You don't have a check for $NULL. There is nothing being returned by the search. 
 Is there any reason why you are scripting this? It can be done completely in a Workflow, no scripting necessary.