One or more work items have been destroyed in the work item tracking database. A constraint error occurred while attempting ...

One or more work items have been destroyed in the work item tracking database. A constraint error occurred while attempting to remove the destroyed work item from the warehouse tables.  This may be due to a Foreign Key constraint introduced by customizations made to the warehouse database.  If this is the case, then the records in the custom table that reference the destroyed work items need to be removed.  The warehouse service will attempt to remove the destroyed work item each time it is processed, until it is successful.
Exception: {0}