[One (M8) Q&A, Help & Troubleshooting] joshew:
I had, a while ago, rooted my phone but eventually decided it wasn't for me, so I reverted back to stock ROM and recovery, etc. When the Marshmallow OTA for my Rogers (Canadian carrier) HTC One M8 arrived, I was excited to upgrade, but when I tried to install the OTA, I got sent to the recovery where this error message popped up partway through the installation:

E:missing bitmap oem_unlock_bg

(Code -1)

E:missing bitmap oem_unlock_bg_yes

(Code -1)

E:missing bitmap oem_unlock_bg_no

(Code -1)

Finding update package . . .

Opening update package . . .

Verifying update package . . .

Installing update . . .

M60QCT.01.002.018

mount: failed to mount /dev/block/platform/msm_sdcc.1/by-na

me/userdata at /data: Device or resource busy

E:unknown command [set_err_msg]

Package expects build fingerprint of htc/rogers_wwe/htc_m8:

5.0.1/LRX22C/463267.3:user/release-keys or htc/rogers_wwe/ht

c_m8:6.0/MRA58K/667457.7:user/release-keys; this device has

htc/rogers_wwe/htc_m8:5.0.1/LRX22C/463267.2:user/release-key

s.

E:Error in /data/data/com.android.providers.downloads/app_f

ota/OTA_M8_UL_M60_SENSE70_MR_Rogers_WWE_6.13.631.7-4.20.631.

3_release_463918.zip

(Status 7)

Installation aborted.

P.S. The bold parts are the stuff that was cut off the screen so I guessed them (or just got the information from other parts of the error message).

This is what fastboot getvar all returns:

(bootloader) version: 0.5

(bootloader) version-bootloader: 3.19.0.0000

(bootloader) version-baseband: 1.25.21331147A1.06G

(bootloader) version-cpld: None

(bootloader) version-microp: Nonez

(bootloader) version-main: 4.20.631.3

(bootloader) version-misc: PVT SHIP S-ON

(bootloader) imei2: Not Support

(bootloader) meid: 00000000000000

(bootloader) product: m8_ul

(bootloader) platform: hTCBmsm8974

(bootloader) modelid: 0P6B16000

(bootloader) cidnum: ROGER001

(bootloader) battery-status: good

(bootloader) battery-voltage: 0mV

(bootloader) partition-layout: Generic

(bootloader) security: on

(bootloader) build-mode: SHIP

(bootloader) boot-mode: FASTBOOT

(bootloader) commitno-bootloader: 4a2bcc8a

(bootloader) hbootpreupdate: 11

(bootloader) gencheckpt: 0

all: Done!

finished. total time: 0.032s

After this happened the first time, I re-rooted to extract the OTA from my phone so that I could get the firmware.zip, recovery.img, and boot.img. I flashed the recovery and boot, re-locked, etc. but then my phone simply stopped booting at the white HTC One logo (the second white HTC screen) or just a black screen (after the first HTC logo but before the second white HTC screen). I then re-locked and tried to flash the firmware from the OTA, resulting in the same problem. I factory reset and erased the cache after all of these things, but nothing worked. I found a Rogers TWRP backup on the forums and used that to get my phone working again, and have tried flashing the recovery and boot images, as well as the firmware from either the Marshmallow OTA or the Lollipop OTA through fastboot or a microSD card, also either having a problem with initial boot stopping at the same places or just the first error message I posted above. Yes, I flashed recovery and boot images with bootloader unlocked, and firmware with bootloader locked after issuing the command fastboot oem rebootRUU. I noticed the boot seems to stop at the second white HTC logo immediately after factory resetting, but would only make it to the black screen (with backlight on) every subsequent reboot, whenever the booting issue happened.

Sometimes when going through some combination of flashing, when I got the phone working again, a Lollipop security patch would not install; however, other times, I could get it to install. No error messages came up when it didn't install, it simply stopped partway through (I think at 24%), before rebooting. At this point, I have Lollipop with my phone working, and have the security patch installed. I am, at the moment, back to the same place I was before attempting to install the Marshmallow OTA the first time.

I have no idea how to get this fixed at this point. I have the Marshmallow OTA and a microSD card. If any of you have any idea how to fix this so I can update to Marshmallow, that would be much appreciated! Sorry for the long read.