Loopback Driver & Code(-9024) Unable to read current state of .

Loopback driver is being used to update information in eDirectory.
The following error is received during the synchronization of a user:  Code(-9024) Unable to read current state of .

DirXML Log Event -------------------
     Driver:   \Tree\Organizaiton\Organizational Unit\Driver Set\Loopback
     Channel:  Publisher
     Object:   \TREE-NAME\Organization\Users\UserName
     Status:   Error
     Message:  Code(-9024) Unable to read current state of .

The clue in this error is in the Channel.  Publisher

For the loopback driver to function properly, it is best to have all processing happen on the Subscriber Channel.  More specifically, have all processing happen in the Event Transformation of the Subscriber Channel.  After all processing is completed veto everything so nothing syncronizes to the "Application".   No processing should occur in the destination direction or make it to the Publisher Channel except under very special circumstances.

The error was received because the Set Destination Attribute was used in policy.  Also, the use of the DestQueryProcessor was used in policy.  Both of these will cause the kind of error seen in this TID.
To fix this, change the Set Destination Attribute to Set Source Attribute and use the SrcQueryProcessor.