Problem  A SharePoint 2013 workflow is receiving information from the SharePoint 2013 site by using the Call HTTP web service action. When you run the workflow, then the following value inside the response is logged: {“error”:{“code”:”-1, Microsoft.SharePoint.Client.ClientServiceException”,”message”:{“lang”:”en-US”,”value”:”The HTTP header ACCEPT is missing or its value is invalid.”}}} The problem occurs, because the SharePoint server needs to know which type of