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.
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).
So, the network admin changed the service user to LOCAL SYSTEM and started the service.
Now, the workflow backend service is started. We have also ran the iisreset.
However, I am still getting the same error:-
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.
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?
UPDATE 1 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.