Action workflow with status Terminated - Why?

I am running an action workflow against user which should only set an date field value. For some reason, I get this kind of error message:

EXCEPTION DATA\r\n\r\nMESSAGE: Microsoft.ResourceManagement.WebServices.Exceptions.PermissionDeniedException: ResourceIsMissing
   at Microsoft.ResourceManagement.WebServices.RequestDispatcher.ExecuteGetAction(RequestType request)
   at Microsoft.ResourceManagement.WebServices.RequestDispatcher.ExecuteAction(RequestType request)
   at Microsoft.ResourceManagement.WebServices.RequestDispatcher.ExecuteAction[ResponseBodyType](RequestType request)
   at Microsoft.ResourceManagement.WebServices.RequestDispatcher.DispatchRequest[ResponseBodyType](RequestType request, Guid requestIdentifier, Object redispatchSingleInstanceKey, Boolean isRedispatch)
   at Microsoft.ResourceManagement.WebServices.RequestDispatcher.DispatchRequest[ResponseBodyType](RequestType request)
   at Microsoft.ResourceManagement.Workflow.Hosting.RequestWorkItemProcessor.DispatchRequest[TResponseType](RequestType request, Boolean applyAuthorizationPolicy)
   at Microsoft.ResourceManagement.Workflow.Hosting.RequestWorkItemProcessor.ProcessGetWorkItem(ReadRequestWorkItem readWorkItem)
   at Microsoft.ResourceManagement.Workflow.Hosting.RequestWorkItemProcessor.ProcessWorkItem(WorkItem workItem)\r\n\r\n**METHOD:Void ProcessRequestResponse(System.Object, System.Workflow.ComponentModel.QueueEventArgs)\r\n\r\n**METHOD:Boolean Run(System.Workflow.ComponentModel.IWorkflowCoreRuntime)\r\n\r\n**METHOD:Void Run()\r\n\r\n

What could be the reason?