[AU] Failed root, now can't OTA from Lollipop to MM [HTC M8]

Hi All;

I've been a lurker for a while, now need further help. My mate has patiently drilled into my head to read XDA to the death, but I'm still stuck. In the last 4 days I've learnt;

-Bootloaders, fastboots, recoverys, TWRP's, stock's, OTAs, custom ROMs, md5's, MID's CID's, and all of that juicy stuff.

Currently my network unlocked M8 is stuck on Lollipop and has an error when attempting to activate the OTA for MM;
(stock recovery screen; )

Code:

---

"Installing update...
M60QCT.01.002.018
mount: failed to mount /dev/block/platform/msm_sdcc.1/by-name/userdata at /data: Device or resource busy
E:unknown command [set_err_msg]
Package expects build fingerprint of htc/telstra_wwe/htc_m8:5.0.01/LRX22C/457188.9:user/release-keys or htc/telstra_wwe/tc_m8:6.0/MRA58K/663331.4:user/release-keys; this device has htc/telstra_wwe/htc_m8:5.0.1/LRX22C/457188.5:user/release-keys.
E:Error in /data/data/com.android.providers.downloads/app_fota/OTA_M8_UL_M60_SENSE70_MR_Telstra_WWE_6.12.841.4-4.19.841.9_release_464352013pnx3icht129py.zip
(Status 7)
Installation aborted."

---

[note the single number difference in bold]

Here's what gets me confused. Orignally this phone was rooted with Lollipop and I lived with it for some time. I decided I wanted MM so my friend showed this XDA post; and it worked perfectly fine the first time (last friday). I then attempted to add TWRP to the phone which worked, and then when I hit the button in TWRP recovery "your phone is not rooted, do you want to root and install SuperSU" it all went to hell after that.

The OS froze at the HTC boot screen and since then I have tried;
--the above procedure exactly to each step and it gets the above typed error at the OTA MM install.
--Restoring MM from the above post links and its stock recovery, but during TWRP restoring of MM, it has a different error.
--Installing Original Lollipop 4.19.841.9 and stock recovery repeatedly, after clearing caches, wiping this and that...
--Attempting to change the "updater-script" file by deleting the assert / getprop line that does the check, has md5 error when installing with TWRP and stock recovery/OS says it's modified, do you want to re-download etc

Currently I'm out of ideas. I honestly don't know what to do. Any suggestions would be much appreciated, I understand you are going to ask for build details etc, so I'll type them below and hope it's enough information.

I'd like to save the current internal storage data but if not, so be it. I'm not actually sure what the "system" and "data" backup from TWRP actually saves. Every time I "wipe" the Boot, System and Data in TWRP, the phone data is still there (such as downloaded images/files). Is it the same data?

Any help or support would greatly be appreciated. Ideally I would like to have the phone on HTC MM rooted, and would like to keep up with OTA's but that's Ron's problem (later on).

Thanks for your help!

--matticas


android
5.0.1
software number
4.19.841.5

kernel version
3.4.0-g3c7a5c1
and@ABM105 #1

baseband version
1.26.214500021.24G_20.69.4196t.01_F

build number
4.19.841.5 CL457188 release-keys

teamwin recovery project
2.7.0.2
(also using TWRP-2.8.7.0)

CID = TELST001
MID = 0P6B11000