Db410 : ubuntu-image -w , flashing binaries snappy fastboot method

Hi,

we are trying to flash the binaries through fastboot method instead of sdcard method, but it is failing at flashing " writable part8.img" . please suggest

fastboot flash writable part8.img
target reported max download size of 268435456 bytes
Invalid sparse file format at header magic
error: write_sparse_skip_chunk: don’t care size 248894109 is not a multiple of the block size 4096
sending sparse ‘writable’ 1/2 (253700 KB)…
error: write_sparse_skip_chunk: don’t care size 248894109 is not a multiple of the block size 4096
error: write_sparse_skip_chunk: don’t care size 248894109 is not a multiple of the block size 4096
OKAY [ 7.994s]
writing ‘writable’ 1/2…
FAILED (remote: buffer overreads occured due to invalid sparse header)
finished. total time: 81.831s

tried below method to extract the binaries

sudo ubuntu-image -w . …/63b0.model --extra-snaps /ifc63b0-kernel_4.4.0-1087.92_arm64.snap --extra-snaps /dragonboard-gadget/ifc63b0-gadget_16.04-0.18_arm64.snap

fastboot flash partition dragonboard-gadget/parts/emmc-gpt-partition/install/blobs/gpt_both0.bin
fastboot flash hyp hyp.mbn
fastboot flash rpm rpm.mbn
fastboot flash sbl1 sbl1.mbn
fastboot flash tz tz.mbn
fastboot flash sec sec.dat
fastboot flash aboot emmc_appsboot.mbn

fastboot flash volumes/dragonboard/boot part6.img
fastboot flash system-boot volumes/dragonboard/part7.img
fastboot flash writable volumes/dragonboard/part8.img

flashed hyp, rpm, sbl1, tz, sec.dat, emmc_appsboot.mbn from this https://releases.linaro.org/96boards/dragonboard410c/linaro/rescue/17.04/dragonboard410c_bootloader_emmc_linux-79.zip