[Moto Z Questions & Answers] karol1981:
im trying to re-lock my moto z with oreo and last security patch , dawnloaded GRIFFIN_OPL27.76-51_cid50_subsidy-DEFAULT_regulatory-DEFAULT_CFC follow instructions from this post and i have problem :

C:\adb>fastboot oem lock begin

...

(bootloader) WARNING: This command erases all user data.

(bootloader) Please re-run this command to continue.

OKAY [ -0.000s]

finished. total time: -0.000s

C:\adb>fastboot oem lock begin

...

(bootloader) Flash valid Android images now

(bootloader) Then re-run this command to lock

OKAY [ 0.002s]

finished. total time: 0.002s

C:\adb>fastboot flash partition gpt.bin

target reported max download size of 536870912 bytes

sending 'partition' (142 KB)...

OKAY [ 0.003s]

writing 'partition'...

(bootloader) Validating 'gpt.default.xml'

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Cancelling 'gpt.default.xml'

FAILED (remote failure)

finished. total time: 0.158s

C:\adb>fastboot flash bootloader bootloader.img

target reported max download size of 536870912 bytes

sending 'bootloader' (7792 KB)...

OKAY [ 0.172s]

writing 'bootloader'...

(bootloader) Validating 'bootloader.default.xml'

(bootloader) Committing 'bootloader.default.xml'

(bootloader) - flashing 'xbl.elf' to 'xbl'

(bootloader) - flashing 'cmnlib.mbn' to 'cmnlib'

(bootloader) - flashing 'cmnlib64.mbn' to 'cmnlib64'

(bootloader) - flashing 'prov64.mbn' to 'prov'

(bootloader) - flashing 'emmc_appsboot.mbn' to 'aboot'

(bootloader) - flashing 'keymaster.mbn' to 'keymaster'

(bootloader) - flashing 'rpm.mbn' to 'rpm'

(bootloader) - flashing 'pmic.elf' to 'pmic'

(bootloader) - flashing 'hyp.mbn' to 'hyp'

(bootloader) - flashing 'tz.mbn' to 'tz'

(bootloader) - flashing 'devcfg.mbn' to 'devcfg'

OKAY [ 4.432s]

finished. total time: 4.605s

C:\adb>fastboot flash logo logo.bin

target reported max download size of 536870912 bytes

sending 'logo' (2670 KB)...

OKAY [ 0.059s]

writing 'logo'...

OKAY [ 0.377s]

finished. total time: 0.436s

C:\adb>fastboot flash boot boot.img

target reported max download size of 536870912 bytes

sending 'boot' (32768 KB)...

OKAY [ 0.747s]

writing 'boot'...

(bootloader) Security version downgrade

(bootloader) Image boot failed validation

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 1.241s

C:\adb>fastboot flash recovery recovery.img

target reported max download size of 536870912 bytes

sending 'recovery' (32772 KB)...

OKAY [ 0.727s]

writing 'recovery'...

(bootloader) Security version downgrade

(bootloader) Image recovery failed validation

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 1.221s

C:\adb>fastboot flash dsp adspso.bin

target reported max download size of 536870912 bytes

sending 'dsp' (16384 KB)...

OKAY [ 0.347s]

writing 'dsp'...

OKAY [ 0.465s]

finished. total time: 0.812s

C:\adb>fastboot flash oem oem.img

target reported max download size of 536870912 bytes

sending 'oem' (63212 KB)...

OKAY [ 1.344s]

writing 'oem'...

(bootloader) Security version downgrade

(bootloader) Image o failed validation

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 1.386s

C:\adb>mfastboot flash system system.img_sparsechunk.0

'mfastboot' is not recognized as an internal or external command,

operable program or batch file.

C:\adb>fastboot flash system system.img_sparsechunk.

error: cannot open 'system.img_sparsechunk.'

C:\adb>fastboot flash system system.img_sparsechunk.0

target reported max download size of 536870912 bytes

sending 'system' (258637 KB)...

OKAY [ 5.486s]

writing 'system'...

(bootloader) Security version downgrade

(bootloader) Image s failed validation

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.530s

C:\adb>fastboot flash system system.img_sparsechunk.1

target reported max download size of 536870912 bytes

sending 'system' (254400 KB)...

OKAY [ 5.401s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.405s

C:\adb>fastboot flash system system.img_sparsechunk.2

target reported max download size of 536870912 bytes

sending 'system' (255942 KB)...

OKAY [ 5.435s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.438s

C:\adb>fastboot flash system system.img_sparsechunk.3

target reported max download size of 536870912 bytes

sending 'system' (251641 KB)...

OKAY [ 5.356s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.361s

C:\adb>fastboot flash system system.img_sparsechunk.4

target reported max download size of 536870912 bytes

sending 'system' (259854 KB)...

OKAY [ 5.521s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.524s

C:\adb>fastboot getvar max-sparse-size

max-sparse-size: 268435456

finished. total time: -0.000s

C:\adb>fastboot oem fb_mode_set

...

OKAY [ 0.001s]

finished. total time: 0.001s

C:\adb>fastboot flash partition gpt.bin

target reported max download size of 536870912 bytes

sending 'partition' (142 KB)...

OKAY [ 0.004s]

writing 'partition'...

(bootloader) Validating 'gpt.default.xml'

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed

(bootloader) Cancelling 'gpt.default.xml'

FAILED (remote failure)

finished. total time: 0.159s

im new with moto z , before moto i have nexus 5 :/

Can you help me guys ?