Video Export get some problem

[Polo1004]

I use SDAVassetExportSession to Export Video from album,but some video has problemsd.
It exported two file,
IMG_0360.MP4(no size,can't play),
IMG_0360.MP4.sb-5087d367-Oy5Lku(unknow file,but it has size the same as the original video)

I hope you will see it soon!Look forward to your reply !
ts....