[T-Mobile LG G5 Guides, News, & Discussion] dksoni411:
FAQ​

Recowvery tool is causing permission errors when I run it through computer's internal HDD storage. What shall I do?

Ans: There are possibly 2 workarounds for that.

A: Extract the zip to external USB storage and Run the tool.

B: Change the name of folder, in which recowvery tool is, to "1" and copy to root of storage e.g. "Computer:\D:\1".

Can I re-lock my bootloader after rooting and TWRP flashing?

Ans: No, as recovery partition modified now, this will brick your device.

Can I use V20C or later on my phone after rooting and flashing TWRP?

And: You can't take OTA after rooting as this might create a brick but fortunately [MENTION=2684188]autoprime[/MENTION] created TWRP flashable zips of firmwares e.g 20c,20f,20i and he might create newer builds too. Anyways here's the Auto Prime's thread, Go to "LG G5 Files" link and download file as per your variant and choice.

I bricked my phone after following this guide and now I can access only download mode, what shall I do now?

I'm on other version than 20a, What shall I do?

Ans: Really? It seems like you're kidding because this guide can never harm your device, It can either do it's work or not but there is no way for it to brick a device (Unless you don't read carefully).

Ans: You can take your phone back to v20a by using the following guide.

Anyways​

You can always bring your phone back to life by following this Back to Life thread.

How to remove encryption in TWRP? or I'm unable to access my phone's internal storage from TWRP, What shall I do?

Ans: So for this process.

a: Boot into twrp.

(you can boot to TWRP by any app or by vol- and power button combination or from option “5” --> “5” in recowvery toolkit (command window).

b: In TWRP, cancel code Windows, Swipe to allow modification then

Click -->Wipe-->Format Data-->type “yes”-->enter.

You need to do this only once. After that you can flash roms and zips unlimited times.

Will this root method work on 20c/d/e/f or others?

Well, it shouldn't. Because I tried this on 20c and it never worked, so I believe it will not work on any software other than 20a because LG removed that exploit to root after 20a. But you can try your luck and tell me if you succeed.

a: Thanks a lot i have one lg g5 h830 and i have some fear to lose the unlocking and i want to modify the phone.

b: Same i have anyone please answer it will i lost the UNLOCKING (Modified by shopkeeper) if i FLASH another ROM?

What are you people trying to ask here?

Bootloader Unlock:

Bootloader can be locked and unlocked anytime you can to do so just by typing commands in fastboot mode. In T-Mobile G5 the fastboot mode do not accept flash command that's why we can only lock and unlock bootloader.

TWRP:

As commands are limited in fastboot mode of T-Mobile G5, we are unable to flash twrp through fastboot mode. So, for this process we rely vulnerability found in G5 firmware. The only currently found method for doing so is by using dirtycow exploit to flash TWRP on H830. Only V20a contains this vulnerability to do so.

Summary:

So to flash TWRP and enjoy freedom of using custom rom (Which I suppose you refer as Unlock to) you need to be on V20a. Which can be flashed easily through LGUP with Uppercut or use my LG FlashTool method (Link in FAQ section). When on V20a firmware simply use this or your preferred method for flashing TWRP.

If you want to go back to stock, simply flash any stock KDZ and lock bootloader. If you want to get TWRP again, simply unlock bootloader and flash V20a kdz (or flash V20a kdz and unlock bootloader) then instal TWRP by using the process.

Important:

Currently our stock firmwares are running Anti-Rollback (ARB 01), LG can increment this whenever they want, whenever LG increase ARB to 02 or upper then you won't be able to get back to ARB 01 firmwares (e.g V20a ) again. Which means you can unlock bootloader but won't be able to flash TWRP as dirtycow is patched after 20a. So you will lose the ability to flash TWRP which means unlocked bootloader is useless unless someone finds another method of flashing TWRP.

So, if you want to stay unlocked, then make sure to install TWRP as described above and flash latest TWRP flashable stock base zips or use other roms like Fulmics or AOSP based. It's very simple and easy .