Fastboot Errors on Lock and RUU

I am trying to install firmware.

I started with an HTC-Dev unlocked S-ON rooted stock HTC M8 (non-HK).
On the command line:

1.
C:\Users\Murad.Eagle\AppData\Local\Android\android-sdk\platform-tools>fastboot oem lock
...
(bootloader) [PGFS] partition_update_pgfs: pg1fs_security
(bootloader) TZ_HTC_SVC_ENC ret = 0
(bootloader) [PGFS] partition_update_pgfs: pg2fs_sec_recovery
(bootloader) Lock successfully...
(bootloader) deinit_lcd
(bootloader) mipi display off
(bootloader) mdp_clock_off
(bootloader) turn off fd8c2308 failed 1 times. Try again...
(bootloader) disable_mmss_clk done
(bootloader) pll1_disable done
(bootloader) TZ_HTC_SVC_DISABLE ret = -1610744452 (0x9FFDFD7C)
(bootloader) [CRITICAL] SPMI write command failure: cmd_id =
0, error
(bootloader) = 4
(bootloader) [CRITICAL] SPMI write command failure: cmd_id =
0, error
(bootloader) = 4
(bootloader) [ERR] Cannot halt SPMI arbiter!!
(bootloader) [INFO] Rebooting device
FAILED (status read failed (No such file or directory))
finished. total time: 1.373s

2.
C:\Users\Murad.Eagle\AppData\Local\Android\android-sdk\platform-tools>fastboot oem rebootruu
...
(bootloader) [ERR] Command error !!!
OKAY [ 0.008s]
finished. total time: 0.009s

In Fastboot, my phone now shows "*** RELOCKED ***"
Why am I getting errors on both steps?