CSOM Workflow API InteropService cannot start new instances of Workflows

Question

On my SharePoint Online site, I have created a SharePoint 2010 Site Workflow through SharePoint Designer.

Now, I want to create an instance and start that workflow through the CSOM Workflow API.

When I first publish the Workflow, everything works beautifully and the Workflow is indeed started (and completes successfully).

The problem occurs when I want to create another instance of the same workflow. Every time I try to run my code the second time, I get the same ClientResult<Guid> back as the first time and the new instance is not started.

I am using the 16.0.0.0 version of Microsoft.SharePoint.Client.dll and Microsoft.SharePoint.Client.WorkflowServices.dll

Here is my code:

using (ClientContext clientContext = new ClientContext("https://mytenant.sharepoint.com/sites/test"))
{
    SecureString passWord = new SecureString();

    foreach (char c in "password".ToCharArray()) passWord.AppendChar(c);

    clientContext.Credentials = new SharePointOnlineCredentials("[email protected]", passWord);

    Web web = clientContext.Web;

    WorkflowAssociationCollection wfAssociations = web.WorkflowAssociations;

    WorkflowAssociation wfAssociation = wfAssociations.GetByName("SP2010SiteWF");

    clientContext.Load(wfAssociation);

    clientContext.ExecuteQuery();

    WorkflowServicesManager manager = new WorkflowServicesManager(clientContext, web);

    InteropService workflowInteropService = manager.GetWorkflowInteropService();

    ClientResult<Guid> resultGuid = workflowInteropService.StartWorkflow(wfAssociation.Name, wfAssociation.Id, wfAssociation.ListId, new Guid(), null);

    clientContext.ExecuteQuery();
}

The problem occurs with List Workflows too. Not only Site Workflows.

Answer 1

Just Modify your code as:

 WorkflowServicesManager manager = new WorkflowServicesManager(clientContext, web);
                InteropService workflowInteropService = manager.GetWorkflowInteropService();
                clientContext.Load(workflowInteropService);
                clientContext.ExecuteQuery();

                ClientResult<Guid> resultGuid = workflowInteropService.StartWorkflow(wfAssociation.Name, new Guid(), new Guid(), new Guid(), null);


                clientContext.ExecuteQuery();

This is working for me.