[Verizon HTC One (M8)] schwty01:
My phone is still functioning, thankfully, but it's all hosed up. The two basic issues are that I lost root in the process of taking the 4.4.3 OTA and that whenever I reboot my phone, it remains stuck on the white HTC screen for about five minutes. The screen eventually shuts off, and then when I wake it up, I have full access to my phone as normal (this happens every time I reboot). Here was my process as best as I can remember to reconstruct it:

My phone was S-OFF and rooted running stock ROM with CWM recovery.

I learned I needed to have stock recovery in order to take the OTA (I now know I'll need to make a backup of the recovery in the future!), so I flashed a stock recovery.

The OTA failed in its installation. Assuming some mod was causing a problem, I decided just to do a factory reset.

I knew I would need to be rooted on 4.4.2 in order to keep root, so I am fairly certain I did check and still had root before taking the OTA.

Upon taking the OTA, it seemed I had lost root access. I tried to run SunShine, but there was a problem with SuperSU ("There is no SU binary installed, and SuperSU cannot install it").

This is where I did what was probably most foolish. Thinking if I could just start over cleanly at 4.4.2, make sure I had root, and then try the OTA again, I flashed the RUU found here. It was my understanding that I could downgrade as long as I was S-OFF and flashed the hboot package first.

The hboot package flashed successfully, but the full package failed.

I'm back to the same problems, and SuperSU still says there is no SU binary installed.

Now I am stuck in this liminal space where I am showing the following software information:

Android version: 4.4.3

HTC Sense version: 6.0

Software number: 2.21.605.2

HTC SDK API level: 6.25

PRI Version: 2.64_002

PRL version: 15333

ERI version: 5

And I am showing the following when I boot into the bootloader:

***UNLOCKED***

M8_WLV PVT SHIP S-OFF

CID-VZW__001

HBOOT-3.16.0.0000

RADIO-1.09.20.0702

OpenDSP-v38.2.2-00542-M8974.0311

OS-1.55.605.2

eMMC-boot 2048MB

I can't get root access because SunShine won't work because SuperSU won't work. And I can't simply uninstall SuperSU and reinstall it because it's installed as a system app, and I don't have root access to uninstall system apps. So I seem to be stuck.

At the most basic level, my question is: Is there a way forward to address both root access and the HTC white screen issue? My hunch is that the white screen is caused by some incompatibility between the hboot downgrade I did and the software update. How can I make sure everything is matching again and that I'm all up-to-date across the board?

And is there a way I can get SuperSU to work so to work on getting root again?

I thought I was being thorough in reviewing instructions and information from this forum, but I had failed as a noobie in not originally making a backup of the stock recovery and then playing it fast and loose there in the middle of the process where I ran into problems taking the OTA.

So now I would appreciate any advice on how to get things straightened out. I so much appreciate the vast wealth of knowledge and helpfulness demonstrated in these forums and would be grateful for any assistance.