Getting User-Assigned-Task Variables

Hi,

I have a task assigned to a user, I am trying to obtain, through an execute script, the process variables of this task. Unfortunately I keep getting an exception in one of the internal classes of LiveCycle. I'm not sure what I'm doing wrong.

Here's the code that I am using (I am using the context of the same user that has the task assigned to):

     ServiceClientFactory userFactory = ServiceClientFactory.createInstance(InvocationContext.getInstance().getContext());
     TypedTaskManagerQueryService tmqs = new TypedTaskManagerQueryService(userFactory);
     List processVariableValues = tmqs.getProcessVariableValues(taskID);

And here's the exception (I cut out a long part of it to make it clearer), it occurs on the getProcessVariableValues method in my code:

     com.adobe.pof.UnknownValueException: Attribute: workflow_principal_id on object: queue:[1] has not been loaded.
          at com.adobe.pof.DefaultGenericObject.getValue(DefaultGenericObject.java:90)
          at com.adobe.workflow.boi.BOIQueueBase.getWorkflowPrincipalId(BOIQueueBase.java:285)
          at com.adobe.idp.taskmanager.dsc.queryservice.TaskManagerQueryServiceImpl.getProcessVariable Values(TaskManagerQueryServiceImpl.java:160)
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

Any insight is greatly appreciated! Thanks

Nic