Troubleshooting Exceptions: System.Workflow.Activities.EventDeliveryFailedException

An EventDeliveryFailedException exception is thrown when an event that is raised from the host cannot be delivered to the workflow instance. Typically, the event is raised from an ExternalDataExchangeService on a workflow instance. This class cannot be inherited.


The following string is added to the event log when this exception is thrown: Event '{1}' on interface type '{0}' for instance id '{2}' cannot be delivered.

When using a state machine workflow, you may get an exception with the message Queue '{0}' is not enabled. This happens when the current state of the state machine is not able to handle a specific event. For example, the message occurs when a state other than the current state contains the EventDrivenActivity that contains the HandleExternalEventActivity that is represented by the queue '{0}'.

See Also


How to: Use the Exception Assistant