I have been struggling with this... for some time now. I have Nintex 2010 and am using an InfoPath form to create a list in Sharepoint that Nintex is referencing. At the approval process in the Workflow, I have tried numerous options to allow the process to complete with an Approval and an Approval letter to the End User. When I fill out the form it works fine, but when I send it to the end user, the task shows "error occurred" and the "Status" column shows "Processing". I have used the "Approved" task box as seen in the picture, I have used the "Approval Status" as seen grayed out in the picture and others. The other legs of the approval process work, as they go the approvers to get approved, but the Auto approval process will not work and errors out at that point in the workflow error screen. Also, I would love to see the Workflow error screen on all the processes that fail, but I can only access it from the email returned from the workflow of one of the employees.