Windows Server 2008: COM error: 0x800706F7 - The stub received bad data

HRESULT GroupStart([in] short iClientId, [in] VARIANT GroupDataArray,
    [out] short* pGroupInstance, [out] long* pCommandId);

// DCAPICOM_GroupData
[
      uuid(F1FE2605-2744-4A2A-AB85-1E1845C280EB),
      helpstring("removed")
]

typedef struct DCAPICOM_GroupData {
      [helpstring("removed")]
      long              m_lImageID;

      [helpstring("removed")]
      unsigned char     m_ucHeadID;

      [helpstring("removed")]
      unsigned char     m_ucPlateID;
} DCAPICOM_GroupData;