Hello, i am trying to run the actions to move attachments from one request form to another and first step in the process was to user call web service action. 

when i set up an action and test connection, it gives me OK however, when i try running it on the preview, it is giving me 500 internal service error. Strange thing is that when i run the workflow it is running from beginning to end without errors but doesn't give me desired result. I am worried that my web call action is not set up correctly, could someone possibly advise? 

I have attached screens of my set up. 

I am trying to use this solution to get attachments from my list items https://nicoleprestby.com/2017/12/19/add-list-item-attachments-to-task-form-using-nintex-workflow-and-forms/

Thank you very much for the help!

<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:m="http://schemas.microsoft.com/sharepoint/soap/">
<soap:Header>
</soap:Header>
<soap:Body>
<m:GetAttachmentCollection>
<m:listName>NCC Reviews</m:listName>
<m:listItemID>{ItemProperty:ID}</m:listItemID>
</m:GetAttachmentCollection>
</soap:Body>
</soap:Envelope>