sample_decode h264 MFXVideoDECODE_Init return MFX_ERR_UNSUPPORTED

HI

I modified the sample_decode to realize the simultaneous decoding of multiple H264 files,but one of the them return  MFX_ERR_UNSUPPORTED when call  MFXVideoDECODE_Init .Why MFXVideoDECODE_Init failed and return  MFX_ERR_UNSUPPORTED ?

Thanks.