Data for this conference directory has not been imported. This conference directory has a duplicate with the same id. One ...

Data for this conference directory has not been imported. This conference
  directory has a duplicate with the same id. One of the two must be deleted
  before import can proceed. Check the admin console to ensure that no other
  pool is assigned a conference directory with the same id. Once only one
  conference directory remains, if the conference directory on this pool
  still exists, check the event log to ensure that synchronization has
  completed. Then retry the import.