title: How to resolve error while trying to publish 2013 workflow via designer. Probably a workflow manager backend user account issue?
body: <p>I am getting error while publishing the 2013 workflow via designer. Also, under sharepoint designer if I try to delete any workflow then the page just refreshes and the workflow does not get deleted.</p>
  <p>I checked the services.msc and found that the workflow backend service was stopped. (this happened as the password of the user under which this serivce was running had changed).</p>
  <p>So, the network admin changed the service user to LOCAL SYSTEM and started the service.</p>
  <p>Now, the workflow backend service is started. We have also ran the iisreset.</p>
  <p>However, I am still getting the same error:-</p>
  <p><em>System.IO.InvalidDataException: A response was returned that did not come from the Workflow Manager. Status code = 503: Service Unavailable
  Service Unavailable
  HTTP Error 503. The service is unavailable.
  Client ActivityId : ee94689c-4e08-b055-fe9c-268d7a94
  Please find attached snapshot.</em></p>
  <p><strong>Is the error as a result of the change in service user? Can you tell me what priviledges should the account running the workflow backend service must have?</strong></p>
  <p><img src="https://i.stack.imgur.com/mpPWv.png" alt="enter image description here" /></p>
  <p><strong>UPDATE 1</strong>
  We have tried to set the account to farm admin and also tried to set it to site admin. Now, for a new web application, I can delete workflows. However, for existing site, I am  not able to delete the existing workflows.. Also, I am not able to publish workflows (present under new and previous sites) and the error is same as described earlier.</p>