台版Butterfly 4.4.2 刷Soul25.0 ROM失敗請教

不好意思跟大家請教求救一下。
最近想把手上的butterfly升級到Sense6，參考論壇上的文件卡在一個步驟fail, 不知道是流程上哪裡出錯了。
感謝

Step1 :
參考耶魯熊 大大的【新手看了也會】hTC Butterfly 4.3.X / 4.4.X Root, 走官方解鎖方式將手機解鎖。
有確認 HBOOT中已經是UNLOCKED, 以及RECOVERY是 ClockworkMod Recovery v6.0.4.5

Step2
參考 瀟湘大的 "[Recovery] 刷5.0版本专用recoveryTWRP2.8.3.0，刷5.0.2必须更新"
在fastboot usb模式下，在WIN7 下執行 "台版蝴蝶_TWRP2.8.3.0英文版.exe"
cmd.exe訊息如下
======================================
target reported max download size of 1514139648 bytes
sending 'recovery' (12268 KB)...
OKAY [ 1.311s]
writing 'recovery'...
OKAY [ 1.052s]
finished. total time: 2.367s
======================================

重新再進RECOVERY MODE已經是Team Win Recovery Project V2.8.3.0

Step3
參考 瀟湘大的 " [实用教程] 【潇湘】蝴蝶全机型固件升级教程"
(a) 在fastboot usb下, 執行cmd.exe，輸入：fastboot oem lock
========================================
(bootloader) Lock successfully...
(bootloader) mipi display off
(bootloader) mipi_dsi_cmds_tx_ext
(bootloader) pm8921_vreg_disable function, vreg_id = 1
(bootloader) pm8921_vreg_disable function, vreg_id = 38
(bootloader) TZ_HTC_SVC_DISABLE ret = 534642044 (0x1FDDFD7C)
(bootloader) Use PSHOLD to reset device.
FAILED (status read failed (Too many links))
finished. total time: 1.227s
=======================================
(b) 這邊不確定 有FAILED是否無關，但是有再確認 HBOOT中已經是RELOCKED
(c) 接著在fastboot usb下, 執行cmd.exe，輸入：fastboot oem rebootRUU
後正常進到黑底hTC的畫面
(d)接著在fastboot usb下, 執行cmd.exe，輸入: fastboot flash zip firmware.zip
我有把Butterfly_Sense6.0_L5.0.2_Soul25.0.zip改名成 firmware.zip, 並且用winmd5free確認過MD5是正確的(b24a26374a65e8476026bce2501e3085)
但是結果卡在 signature check 是失敗的，我按照升級教程提的，做了第二次的fastboot flash zip firmware.zip, 結果也是看到signature check失敗，沒有看到進度條。
======================================================
D:\hTC Butterfly Root\adb>fastboot oem rebootRUU
< waiting for device >
...
(bootloader) Start Verify: 3
OKAY [ 0.038s]
finished. total time: 0.038s

D:\hTC Butterfly Root\adb>fastboot flash zip firmware.zip
sending 'zip' (1132442 KB)...
OKAY [ 44.140s]
writing 'zip'...
(bootloader) signature checking...
FAILED (remote: 12 signature verify fail)
finished. total time: 191.442s

D:\hTC Butterfly Root\adb>fastboot flash zip firmware.zip
sending 'zip' (1132442 KB)...
OKAY [ 44.210s]
writing 'zip'...
(bootloader) signature checking...
FAILED (remote: 12 signature verify fail)
finished. total time: 193.150s
=====================================================
我有試過重新 從Step1開始做，跳過Step2更新recoveryTWRP2.8.3.0的動作直接做step3, 結果還是一樣。
所以不知道到底是哪出了問題，還請各位高手幫忙。
還是我可以直接進RECOVERY, 直接把zip install進去?但怕磚不敢嘗試。
謝謝