I have try also another firmware, but still same error.
DC Phoenix 0.0.0.125
user:
Looking for a device in upgrade mode
No devices detected in upgrade mode
Device found: RSV4C19923002920
Detecting recovery partition
File size: 3,808,201,076 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
ERECOVERY_KERNEL partition found
ERECOVERY_RAMDISK partition found
ERECOVERY_VENDOR partition found
4/1/2020 7:34:39 PM Starting to try Rescue Recovery...
Looking for a device in fastboot mode
Device found: RSV4C19923002920
Getting IMEI...
Getting build number...
Getting model ...
Getting battery state...
Getting backdoor info...
Getting lock state info...
Getting lock boot info...
Build number: :STK-L01M 10.0.0.185(C316E4R4P1)
Model: STK-L21
Vendor/Country: vodacom/za
Battery state: 4256mv
OEM lock state info:
FB LockState: LOCKED
USER LockState: LOCKED
OEM get bootinfo:
locked
Getting base version...
Base Version: STK-LGRP3-OVS 10.0.0.185
Getting cust version...
Cust Version: STK-L01M-CUST 10.0.0.4(C316)
Getting preload version...
Preload Version: STK-L01-PRELOAD 10.0.0.1(C316R4)
Process identifier:23720284
Erasing ver .. .
File size: 3,808,201,076 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
Writing rescue_recovery_kernel partition
RESCUE_RECOVERY_KERNEL partition update ...OK
Writing rescue_recovery_ramdisk partition
RESCUE_RECOVERY_RAMDISK partition update ...OK
Writing rescue_recovery_vendor partition
RESCUE_RECOVERY_VENDOR partition update ...OK
Uptade recovery parttion OK
USB Device REMOVAL
Type: @oem24.inf,%singlebootloaderinterface%;Android Bootloader Interface
VidPid: VID_18D1&PID_D00D
Instance id: RSV4C19923002920
Looking for device in upgrade mode...
USB Device INSERTION
Type: @oem20.inf,%busfilter.devicedesc%;USB Composite Device
VidPid: VID_12D1&PID_107E
Instance id: RSV4C19923002920
COM7: Android Adapter PCUI (COM7)
COM6: DBAdapter Reserved Interface (COM6)
Enter recovery mode OK
4/1/2020 7:35:19 PM Starting to write device in UPGRADE mode...
Device found: RSV4C19923002920
Old slow algo NOT selected
4/1/2020 7:35:21 PM start to write update file
File to update: D:\Huawei FRP Solution\STK-L21 Y9 Prime\5._STK-L21_9.1.0.277(C185E2R4P1).APP
File size: 3,808,201,076 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
Process identifier:23720289
Validating file...
Looking for attached port...
Preparing to write...
Writing file 1 of 44: SHA256RSA...OK
Writing file 2 of 44: CRC...OK
Writing file 3 of 44: BASE_VERLIST...
Error downloading file 3 of 44
Error writing software
4/1/2020 7:35:39 PM Writing device finished with ERROR
another version firmware also same error.
Looking for a device in upgrade mode
No devices detected in upgrade mode
Device found: RSV4C19923002920
Detecting recovery partition
File size: 3,892,426,284 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
ERECOVERY_KERNEL partition found
ERECOVERY_RAMDISK partition found
ERECOVERY_VENDOR partition found
4/1/2020 7:52:11 PM Starting to try Rescue Recovery...
Looking for a device in fastboot mode
Device found: RSV4C19923002920
Getting IMEI...
Getting build number...
Getting model ...
Getting battery state...
Getting backdoor info...
Getting lock state info...
Getting lock boot info...
Build number: :STK-L01M 10.0.0.185(C316E4R4P1)
Model: STK-L21
Vendor/Country: vodacom/za
Battery state: 4269mv
OEM lock state info:
FB LockState: LOCKED
USER LockState: LOCKED
OEM get bootinfo:
locked
Getting base version...
Base Version: STK-LGRP3-OVS 10.0.0.185
Getting cust version...
Cust Version: STK-L01M-CUST 10.0.0.4(C316)
Getting preload version...
Preload Version: STK-L01-PRELOAD 10.0.0.1(C316R4)
Process identifier:23720423
Erasing ver .. .
File size: 3,892,426,284 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
Writing rescue_recovery_kernel partition
RESCUE_RECOVERY_KERNEL partition update ...OK
Writing rescue_recovery_ramdisk partition
RESCUE_RECOVERY_RAMDISK partition update ...OK
Writing rescue_recovery_vendor partition
RESCUE_RECOVERY_VENDOR partition update ...OK
Uptade recovery parttion OK
USB Device REMOVAL
Type: @oem24.inf,%singlebootloaderinterface%;Android Bootloader Interface
VidPid: VID_18D1&PID_D00D
Instance id: RSV4C19923002920
Looking for device in upgrade mode...
USB Device INSERTION
Type: @oem20.inf,%busfilter.devicedesc%;USB Composite Device
VidPid: VID_12D1&PID_107E
Instance id: RSV4C19923002920
COM7: Android Adapter PCUI (COM7)
COM6: DBAdapter Reserved Interface (COM6)
Enter recovery mode OK
4/1/2020 7:52:55 PM Starting to write device in UPGRADE mode...
Device found: RSV4C19923002920
Old slow algo NOT selected
4/1/2020 7:52:58 PM start to write update file
File to update: D:\Huawei FRP Solution\STK-L21 Y9 Prime\1_312_.APP
File size: 3,892,426,284 bytes
Current version(BASE_VER): STK-LGRP3-OVS 9.0.1.170
Process identifier:23720430
Validating file...
Looking for attached port...
Preparing to write...
Writing file 1 of 44: SHA256RSA...OK
Writing file 2 of 44: CRC...OK
Writing file 3 of 44: BASE_VERLIST...
Error downloading file 3 of 44
Error writing software
4/1/2020 7:53:14 PM Writing device finished with ERROR