[Moto G4 Questions & Answers] hyperblau:
Do you mean that you were able to flash and re-lock?

I just used the firmware you provided, no luck though. Still getting the "Still require signed boot.img" error when it tried to finish up the oem lock. And it appears it doesn't actually flash correctly either, version is still 6.0.1. Not sure what I'm doing wrong here.

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot oem lock begin
...
(bootloader) WARNING: This command erases all user data.
(bootloader) Please re-run this command to continue.
OKAY [ 0.005s]
finished. total time: 0.006s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot oem lock begin
...
(bootloader) Flash valid Android images now
(bootloader) Then re-run this command to lock
OKAY [ 0.012s]
finished. total time: 0.012s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash partition gpt.bin
target reported max download size of 536870912 bytes
sending 'partition' (32 KB)...
OKAY [ 0.005s]
writing 'partition'...
(bootloader) Security version downgrade

(bootloader) Image primary_gpt failed validation

(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.044s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash bootloader bootloader.img
target reported max download size of 536870912 bytes
sending 'bootloader' (3651 KB)...
OKAY [ 0.119s]
writing 'bootloader'...
(bootloader) validating: bootloader.default.xml ...
(bootloader) will pass: flash:aboot
(bootloader) will pass: flash:rpm
(bootloader) will pass: flash:tz
(bootloader) will pass: flash:hyp
(bootloader) will pass: flash:cmnlib
(bootloader) will pass: flash:keymaster
(bootloader) will pass: flash:sbl1
(bootloader) committing: bootloader.default.xml ...
(bootloader) - flashing 'emmc_appsboot.mbn' to 'aboot'
(bootloader) - flashing 'rpm.mbn' to 'rpm'
(bootloader) - flashing 'tz.mbn' to 'tz'
(bootloader) - flashing 'hyp.mbn' to 'hyp'
(bootloader) - flashing 'cmnlib.mbn' to 'cmnlib'
(bootloader) - flashing 'keymaster.mbn' to 'keymaster'
(bootloader) - flashing 'sbl1.mbn' to 'sbl1'
OKAY [ 0.394s]
finished. total time: 0.514s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash logo logo.bin
target reported max download size of 536870912 bytes
sending 'logo' (2105 KB)...
OKAY [ 0.069s]
writing 'logo'...
OKAY [ 0.070s]
finished. total time: 0.141s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash boot boot.img
target reported max download size of 536870912 bytes
sending 'boot' (16384 KB)...
OKAY [ 0.519s]
writing 'boot'...
(bootloader) Security version downgrade

(bootloader) Image boot failed validation

(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.686s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash recovery recovery.img
target reported max download size of 536870912 bytes
sending 'recovery' (16484 KB)...
OKAY [ 0.523s]
writing 'recovery'...
(bootloader) Security version downgrade

(bootloader) Image recovery failed validation

(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 0.691s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash dsp adspso.bin
target reported max download size of 536870912 bytes
sending 'dsp' (16384 KB)...
OKAY [ 0.518s]
writing 'dsp'...
OKAY [ 0.298s]
finished. total time: 0.818s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash oem oem.img
target reported max download size of 536870912 bytes
sending 'oem' (96490 KB)...
OKAY [ 3.039s]
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: 3.099s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.0
target reported max download size of 536870912 bytes
sending 'system' (261001 KB)...
OKAY [ 8.213s]
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: 8.278s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.1
target reported max download size of 536870912 bytes
sending 'system' (250858 KB)...
OKAY [ 7.893s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 7.921s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.2
target reported max download size of 536870912 bytes
sending 'system' (254625 KB)...
OKAY [ 8.012s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.040s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.3
target reported max download size of 536870912 bytes
sending 'system' (261577 KB)...
OKAY [ 8.231s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.249s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.4
target reported max download size of 536870912 bytes
sending 'system' (260443 KB)...
OKAY [ 8.194s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.230s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.5
target reported max download size of 536870912 bytes
sending 'system' (248842 KB)...
OKAY [ 7.830s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 7.855s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.6
target reported max download size of 536870912 bytes
sending 'system' (259549 KB)...
OKAY [ 8.167s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.209s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash system system.img_sparsechunk.7
target reported max download size of 536870912 bytes
sending 'system' (82497 KB)...
OKAY [ 2.599s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 2.616s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash modem NON-HLOS.bin
target reported max download size of 536870912 bytes
sending 'modem' (76954 KB)...
OKAY [ 2.424s]
writing 'modem'...
OKAY [ 1.073s]
finished. total time: 3.499s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase modemst1
erasing 'modemst1'...
OKAY [ 0.022s]
finished. total time: 0.023s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase modemst2
erasing 'modemst2'...
OKAY [ 0.032s]
finished. total time: 0.033s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot flash fsg fsg.mbn
target reported max download size of 536870912 bytes
sending 'fsg' (2040 KB)...
OKAY [ 0.067s]
writing 'fsg'...
OKAY [ 0.058s]
finished. total time: 0.128s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase cache
erasing 'cache'...
OKAY [ 0.016s]
finished. total time: 0.017s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase userdata
erasing 'userdata'...
OKAY [ 0.031s]
finished. total time: 0.032s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase customize
erasing 'customize'...
OKAY [ 0.015s]
finished. total time: 0.016s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot erase clogo
erasing 'clogo'...
OKAY [ 0.015s]
finished. total time: 0.016s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot oem lock
...
(bootloader) Still require signed boot.img
OKAY [ 0.004s]
finished. total time: 0.005s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>fastboot oem lock
...
(bootloader) Still require signed boot.img
OKAY [ 0.004s]
finished. total time: 0.005s

F:\apps\AndroidTools\Moto G4 Plus XT1640-43 ATHENE NPJ25.93-14 Stock Img>