In order to match and load a runnable instance in the store, the requesting InstanceOwner must have specified a workflow ...

In order to match and load a runnable instance in the store, the requesting InstanceOwner must have specified a workflow host type when it was created. To do so, add a key-value pair to the CreateWorkflowOwnerCommand.InstanceOwnerMetadata property bag when issuing the command. The key is the WorkflowHostType key provided in the documentation. The value must be an XName and match that of the instances being loaded.