Problem Statement: Start a  SharePoint 2013 designer Reusable Workflow with STS Authenticated User. We are trying to start to SharePoint 2013 designer Reusable Workflow withSTS authenticated user using code but when we do that, we get following error. RequestorId: a3ce6dc6-31ec-23f3-0000-000000000000. Details: RequestorId: a3ce6dc6-31ec-23f3-0000-000000000000. Details: An unhandled exception occurred during the execution of the workflow instance. Exception details: System.ApplicationException: HTTP 401 {"error_description":"The server was unable to process the request due to an internal error. For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the <serviceDebug> configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs."} {"x-ms-diagnostics":["3001000;reason=\"There has been an error authenticating the request.\";category=\"invalid_client\""],"SPRequestGuid":["a3ce6dc6-31ec-23f3-b3ab-aef56fc7e299"],"request-id":["a3ce6dc6-31ec-23f3-b3ab-aef56fc7e299"],"X-FRAME-OPTIONS":["SAMEORIGIN"],"SPRequestDuration":["65"],"SPIisLatency":["0"],"Server":["Microsoft-IIS\/8.0"],"WWW-Authenticate":["Bearer realm=\"de9da885-f7bf-4564-a3a5-

Alternate approach we are following : We have created a windows authenticated user and gave him all the necessary permission to trigger the workflow(contribute, full control). Then we are creating the User token for that user and opening the site with the help of the generated user token. By this approach workflow is getting triggered.

The problem in this approach is after ¾ days it gives error when trying to kick off workflow from code with user who has not logged in as we are using this AD user only for kickoff purpose.

InvalidOperationException: Operation is not valid due to the current state of the object

MCTS Sharepoint 2010, MCAD dotnet, MCPDEA, SharePoint Lead