always gove this error
WARNING: oppo custom is empty(invalid)!
AUTH info: , version: 0
Firmware package: Oppo-A71
BROM version[1]: 7.2045.2.0
DA: MTK_AllInOne_DA.bin
hash: 7a3c72dad63c06bd1a67cce0354e7286cf26ab6a, size: 15.07 MiB
version: 3.3001.2020-11-02021/03/15 23:20:58, start addr: 0x40000800
Connecting to BootROM...
Power off the phone, disconnect and reconnect the battery(if possible) and connect USB cable...
Hold the VOL UP to force MediaTek BootROM.
Scanning BootROM or Preloader port... Done
Detected [PL] MediaTek PreLoader USB VCOM_V1633 (Android) (COM29)
Connection status: EHCI:HUB[#5]:USB 2.10 High-Speed
USB Driver: [MediaTek Inc.] wdm_usb, version: 3.0.1504.0, date: 1-22-2015
Connecting Bootrom...
Sending Download Agent...
Platform: MT6750, hw ver: 0xCB00, sw ver: 0x0001
Secure ver: 0x00, BL ver: 0x00
SRAM size: 224 KiB
DRAM size: 3 GiB
Storage type: eMMC
Card/BGA: BGA (Discrete embedded)
Manufacturer ID: 0x15 (Samsung)
Product name: GE6BMB (0x474536424d42), rev: 0x03, serial number: 0x2EDBD00C
Manufacturing date: Jul 2017
CID: 15010047 4536424D 42032EDB D00C7419
Capacity: 14.57 GiB (15,646,851,072 bytes)
Boot1: 4096 KiB
Boot2: 4096 KiB
RPMB: 4096 KiB
User area: 14.56 GiB(15,634,268,160 bytes)
USB speed: High-Speed
platform: MT6755, S01, cpu abi: arm64-v8a
manufacturer: OPPO
board: full_oppo6750_17351, name: CPH1717
brand: OPPO, model: CPH1717 (OPPO A71)
build id: N4F26M, version: 7.1.1 [Nougat] (CPH1717EX_11_A.02_170815)
build date: Tue Aug 15 01:16:31 CST 2017, security patch: 2017-06-05
build description: full_oppo6750_17351-user 7.1.1 N4F26M 1502731011 release-keys
WARNING: oppo custom is empty(invalid)!
Internal storage: 3 GiB
crypto state: unencrypted