em up room 520 bằng nokia care suite thì nó hiện lỗi 0x00030007: The boot loaders in FFU file are not signed for this device. RKH of device: 7C81AABA97E4904DB782605A6C74A59480361E5A363337B2EF5B8F925763110B. RKH of FFU image: F771E62AF89994064F77CD3BC16829503BDF9A3D506D3FACECAEF3F808C868FD Exception: Nokia.CareSuite.PlugIns.MurzimRecovery.RecoveryDialog.MurzimProgrammingException: 0x00030007: The boot loaders in FFU file are not signed for this device. RKH of device: 7C81AABA97E4904DB782605A6C74A59480361E5A363337B2EF5B8F925763110B. RKH of FFU image: F771E62AF89994064F77CD3BC16829503BDF9A3D506D3FACECAEF3F808C868FD at Nokia.CareSuite.PlugIns.MurzimRecovery.RecoveryDialog.RecoveryDialogModel.Flash() at Nokia.CareSuite.PlugIns.MurzimRecovery.RecoveryDialog.RecoveryDialogModel.<HandleDownloadVariantPackageCompleted>b__b(Object state) bác nào giúp em với