Not able to start out of the box approval workflow programmatically

Question

We have a requirement to start an out of the box workflow from a .NET web service.
We are using the StartWorfklow method:
wfManager.StartWorkflow(item, association, association.AssociationData
we are getting the below error message at the above line of code: Attempted to perform an unauthorized operation.. Data: System.Collections.ListDictionaryInternal
Then, we tried:
SPSecurity.RunWithElevatedPrivileges(delegate()
        wfManager.StartWorkflow(item, association, association.AssociationData,
SPWorkflowRunOptions.Synchronous);
Now, the workflow got canceled automatically with "Failed on Start" status. In the "Workflow History", it is showing 2 records with "was canceled by System Account." & "failed to start" in the description
column.
Please advise.

Answer 1

Hi Zhengyu,
1. I've already done that:
a) when "SPSecurity.RunWithElevatedPrivileges(delegate()"
is used, there are no errors showing up and code gets executed. However, the workflow failed to start.
b) When I don't use elevated privileges, the code is showing an error (Attempted to perform an unauthorized operation.. Data: System.Collections.ListDictionaryInternal) when
it tries to start the workflow (StartWorkflow method).
2. The workflow starts with no issues through UI. I tried it using "System Account" and another account.
3. I tried also "Collect Feedback" workflow template. Same results...
You can find the code below:
public
stringStartItemWorkflow(stringsitePath,
stringlibraryName,
stringfileName)
stringreturnVal =
String.Empty;
stringwfName =
"VPApprovalWF";
SPUserTokentoken = GetSecurityToken(sitePath);
try
using(Microsoft.SharePoint.SPSiteportalSite
= newMicrosoft.SharePoint.SPSite(sitePath,
token))
using(SPWebportalWeb
= portalSite.OpenWeb())
                    portalWeb.AllowUnsafeUpdates =
true;
SPListlist = portalWeb.Lists[libraryName];
SPQueryfileQuery =
newSPQuery();
                    fileQuery.Query =
String.Format("<Where><Contains><FieldRef
Name='FileLeafRef' /><Value Type=\"User\">{0}</Value></Contains></Where>", fileName);
                    fileQuery.ViewAttributes =
"Scope='RecursiveAll'";
SPListItemCollectionlistItemCol = list.GetItems(fileQuery);
SPWorkflowManagerwfManager = portalSite.WorkflowManager;
SPWorkflowAssociationCollectionassociationCollection
= list.WorkflowAssociations;
if(listItemCol.Count > 0)
foreach(SPListItemitem
inlistItemCol)
if(associationCollection.Count > 0)
foreach(SPWorkflowAssociationassociation
inassociationCollection)
if(association.Name == wfName)
                                        item.Update();
                                        association.AutoStartChange
=
true;
                                        association.AutoStartCreate
=
false;
                                        association.AssociationData
=
String.Empty;
                                        StartWF(wfManager,
item, association);
                                        returnVal +=
"Workflow Started";
break;
else
                                returnVal +=
"No workflows are attached to the library.";
else
                        returnVal +=
"A file with the name provided doesn't exist";
                    portalWeb.AllowUnsafeUpdates =
false;
catch(Exceptionex)
            returnVal +=
"Workflow not started, reason: "+
String.Format("Source:
{0}. Stack Trace: {1}. Inner Exception:{2}. Message: {3}. Data: {4}", ex.Source, ex.StackTrace, ex.InnerException, ex.Message, ex.Data);
returnreturnVal;
SPUserTokenGetSecurityToken(stringsitePath)
SPUserTokentoken =
null;
SPSecurity.RunWithElevatedPrivileges(delegate()
            Microsoft.SharePoint.
SPSiteportalSite =
newMicrosoft.SharePoint.SPSite(sitePath);
            token = portalSite.RootWeb.EnsureUser(
"DOMAIN\\ADMIN-USER").UserToken;
            portalSite.Dispose();
returntoken;
privatestaticvoidStartWF(SPWorkflowManagerwfManager,
SPListItemitem,
SPWorkflowAssociationassociation)
SPSecurity.RunWithElevatedPrivileges(delegate()
            wfManager.StartWorkflow(item, association, association.AssociationData,
SPWorkflowRunOptions.Synchronous);
Thank you all for your help.
Regards,