[Android Q&A, Help & Troubleshooting] klassic1:
This is what i get ..

D:\platform-tools-latest-windows\platform-tools>fastboot devices

TA391006KH fastboot

D:\platform-tools-latest-windows\platform-tools>fastboot flash partition D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\gpt.bin

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:partition: not found

target reported max download size of 536870912 bytes

sending 'partition' (32 KB)...

OKAY [ 0.016s]

writing 'partition'...

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 0.393s

D:\platform-tools-latest-windows\platform-tools>fastboot flash bootloader D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\bootloader.img

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:bootloader: not found

target reported max download size of 536870912 bytes

sending 'bootloader' (2699 KB)...

OKAY [ 0.155s]

writing 'bootloader'...

(bootloader) flashing aboot ...

(bootloader) flashing sbl1 ...

(bootloader) flashing pmic ...

(bootloader) flashing rpm ...

(bootloader) flashing tz ...

(bootloader) flashing hyp ...

(bootloader) flashing sdi ...

OKAY [ 1.637s]

finished. total time: 1.805s

D:\platform-tools-latest-windows\platform-tools>fastboot flash logo D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\logo.bin

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:logo: not found

target reported max download size of 536870912 bytes

sending 'logo' (3687 KB)...

OKAY [ 0.081s]

writing 'logo'...

OKAY [ 0.116s]

finished. total time: 0.204s

D:\platform-tools-latest-windows\platform-tools>fastboot flash boot D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\boot.img

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:boot: not found

target reported max download size of 536870912 bytes

sending 'boot' (40960 KB)...

OKAY [ 0.985s]

writing 'boot'...

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 1.702s

D:\platform-tools-latest-windows\platform-tools>fastboot flash recovery D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\recovery.img

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:recovery: not found

target reported max download size of 536870912 bytes

sending 'recovery' (41040 KB)...

OKAY [ 0.961s]

writing 'recovery'...

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 1.728s

D:\platform-tools-latest-windows\platform-tools>fastboot flash system D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\system.img_sparsechunk.0

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:system: not found

target reported max download size of 536870912 bytes

sending 'system' (257199 KB)...

OKAY [ 5.813s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 6.232s

D:\platform-tools-latest-windows\platform-tools>fastboot flash system D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\system.img_sparsechunk.1

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:system: not found

target reported max download size of 536870912 bytes

sending 'system' (255632 KB)...

OKAY [ 5.848s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.917s

D:\platform-tools-latest-windows\platform-tools>fastboot flash system D:\XT1572_CLARK_RETEU_6.0.1_MPHS24.107-58-5_cid7_subsidy-DEFAULT_CFC.xml\system.img_sparsechunk.2

(bootloader) slot-count: not found

(bootloader) slot-suffixes: not found

(bootloader) slot-suffixes: not found

(bootloader) has-slot:system: not found

target reported max download size of 536870912 bytes

sending 'system' (255866 KB)...

OKAY [ 5.851s]

writing 'system'...

(bootloader) Invalid signed image

(bootloader) Preflash validation failed

FAILED (remote failure)

finished. total time: 5.920s