To select RUU, be sure to read:Information about phone versions for choosing stock firmware based on MID and CID

Before asking a question in the topic, you need to collect data about the phone using the 'fastboot getvar all' command in download mode and plus provide a photo from the screen of download mode itself and lay out (without IMEI) all this together with the question.
You need to upload data under the spoiler.

The authors of the manuals or anyone else on this forum is not responsible for what you have done, all responsibility lies only with you !!!

Instructions

• ^ⓈHow to reboot to the bootloader and then to download mode on HTC U12 +
  
• ^ⓈHow to reboot in stock rekaveri at U12 +, Video
  
• How to unlock the bootloader
  
• ^ⓈHow to install RUU or firmware in * .zip format with extSD or OTG
  
• ^ⓈHow to flash RUU.zip manually through a PC
  
• ^ⓈHow to catch HTC link to OTA arriving, and where is the downloaded OTA by air
  
• ^ⓈHow to install OTA manually from extSD or PC
  
• How to check Oreo / restore functionality requirements OTA
  
• How to convert the Chinese version of U12 + to EMEA with S-OFF. User experience.
  
• How to change CID with S-ON, without SunShine
  
• Translated TWRP and Magisk installation instructions from the XDA forum
  
• Installation Instructions TWRP and Magisk SU Example: Put magisk at 1.62
  
• How to get pristine stock Boot and System.Image, create / restore Untouched Backup
  
• An example of how to make Untouched Backup to return to the stock state of an untouched system for receiving OTA
  
• ^ⓈHow to make your data backup in TWRP
  
• ^ⓈHow to fully save / restore all your user data.
  
• ^ⓈHow to check which software number is freely allowed to roll back without forcibly lowering the software
  
• ^ⓈForce downgrade from S-ON (Rollback to software below)
  
• Option of forced reduction software from Route "on his knees" without a PC.
  
• ^ⓈSwitch to on the other slot with a pristine system and receiving OTA without data loss. How to get the update OTA Root.
  
• Restore the system integrity for further updates on the PTA while retaining all of their data
  
• ^ⓈInstructions for use HTC Utilities RUU / ROM Decryption Tool
  
• To change MID
  
• How to close the loader correctly and get the status Relocked
  
• How to enable the bootloader OEM-unlock item in the For Developers menu with TWRP or root
  
• How to restore Face Unlock if RUU does not help. 2. Another method is "on his knees" without a PC.3. User Experience.
  
• Switching to 9 android with saving data and getting root using an example
  
• Firmware hosd_signed.img while rolling back a Pie and Pie RUU firmware to Oreo
  
• Backup data after flashing RUU Pie
  
• Pie recovery backup data at a constant TWRP
  
• Obtaining permanent TWRP FOR PIE WITH RETENTION data encryption and without it
  
• Getting a working TVRP without scripts
  
• Deciphering Data
  
• Data backup / restoration preserving encryption
  

Useful information

• DSP_for_U12 + _TWRP_Flashable
  
• reception setting signal
  
• Mountroot
  
• PC configuration option to work with adb utilities.
  
• HTC U12 + Partition List
  
• SunShine application for temporary S-OFF
  
• Fix FaceUnlockFix for the full version of ViperU12 +
  
• Fix, FaceUnlockFix 1.0.0 module for Magisk
  
• The script for the forced lowering TWRP Software
  
• Leaving the phone from a cyclic reboot
  
• User experience, return from EXODUS1 1.57 to IMAGINE 1.30 for devices with a blocked bootloader
  
• HTC applications
  
• Installing / reinstalling Magisk v17 affects Wi-Fi performance
  
• Installing the HTC Clock Widget
  
• Option to unlink the phone from a Google account
  
• ^ⓈWorkaround Google Account (FRP) with a closed loader
  
• How to include the number of application messages on its shortcut
  
• The script for the TWRP 5 changes to the ACC's xml-file
  
• @Xposed

  • Install and configure Xposed
    
  • Install Xposed v0.4.4.4_alpha for Android 9. Topic onsavagemessiahzine.com
    
  • Working with EdXposed
    
  • EdXposed and GPay
    

  
  
  
  
  ^Ⓢ- the instruction can be executed on a full 100% drain with a locked bootloader.
  

On U12 +, Exodus1 no longer has a recovery partition. Stock recovery is sewn into boot.
There are two options for custom recovery:
I) . TemporaryTWRP .img
^ⓈYou can boot into it from the bootloader command:

This is a great opportunity to boot into TWRP without changing boot.img. On this device, an opportunity is opened for experienced users to launch TWRP and have a 100% full drain with a locked bootloader, which allows a lot, for example, such as: forced rollback to the software below, make / restore your data backup , removing phone lock keys, accessing system files, etc.
After rebooting, the temporary TWRP disappears.
Ii) . Permanent (Permanent)TWRP .zip loaded into ramdisk.
There are two main options for installing a permanent TWRP (the bootloader must be unlocked, Unlocked):
1. From the temporary TWRP.img, flash TWRP.zip
2. Install TWRP.zip from Magisk Manager (click + in the modules section).
Due HTC introduced an additional check in touchscreen driver, when loaded into TWRP display will be inactive. For this purpose, after flash TWRP constant need to immediately flash patch for core stock hex patcher (boot patches both slots), it can be sewn from both TWRP, and from Magisk Manager. Custom kernel have been going to patch this problem, flash the hex patcher in the presence of a custom kernel is not required. At the core of katabatic with hex patcher will not work in the command boot recovery "adb reboot recovery", also loading in the recovery of Magisk Manager and to load the recovery of the most TWRP. Booting into bootloader recovery of buttons.
After installing a permanent TWRP, you need to reinstall Magisk, if you need a root, then flash magisk.zip. If the root is not needed, then go to Advanced and select Fix Recovery Bootloop in order to avoid a bootoot when entering the system.
TWRP needs to be selected and installed according to its security patch.

• TWRP theme for U12 + on xda.
  
• All official versions of TWRP. Download.
  
• Download touchscreen_hexpatcher.zip Download from AFH
  
• Flasher permanent TWRP.
  

Unofficial TWRP from Team Venom:

Informal TWRP from @CaptainThrowback:

Route access to U12 + can be obtained from Magisk. You can install it in two main options:
Initial data: Unlocked Unlocked bootloader configured by PC for adb utilities.
1. Installation option with TWRP.
1a. Flash magisk.zip from TWRP. The Magisk Manager application should be installed during firmware. If not, install MagiskManager.apk. Done, the root is installed.
1b. Another installation option by firmware from TWRP patched boot.img
- Install the application MagiskManager.apk
- Copy to the phone the original untouched boot_signed.img corresponding to the current software.
- In the Magisk Manager application, double-click Install ->Select and patch the file.
- Select the untouched boot_signed.img stored on the phone and wait for the patch to finish, we get the patched patched_boot.img
- We are rebooted in TWRP. Click reboot to see the active slot. We switch to inactive and back to the active slot.
- In the menu, select Install - Install img - choose to install the received patched patched_boot.img, wait for the end of the process.
- We are rebooted into the system. Done, the root is installed.

2. Installation option without TWRP.
- Install the application MagiskManager.apk
- Copy to the phone the original untouched boot_signed.img corresponding to the current software.
- In the Magisk Manager application, double-click Install ->Select and patch the file.
- Select the untouched boot_signed.img stored on the phone and wait for the patch to finish, we get the patched patched_boot.img
- In any way, copy the patched boot file on the PC to the folder where the adb utilities are. Or:
- Connect to the PC and transfer the file to the PC in the adb folder, execute the command:

- We load in download mode:

- Check the current slot:

- We use the received active slot in the teams as a prefix. The following commands, depending on the active slot, flash the patched boot.img into the active slot:
if slot A

if slot B

- We are rebooted into the system:

Done, the root is installed.
After installing the root, you need to restore the phone to unlock by face, Photo Password (Face Unlock),according to this instruction.

• Magisk theme on xda. Download the latest stable or beta version, Magisk Manager app, Uninstaller.
  
• Magisk theme onsavagemessiahzine.com
  
• Theme on xda how to install root on U12 +
  

Question - "B"
The answer is "O"

AT . What is A / B Parition on our phone?
O . Additionally, the second discrete region, for example, B, allocated on the phone’s internal memory and designed for seamless and guaranteed receipt of updates to it, when the first, in Example A, with all the data saved is active. In details on xda , or for example here

AT . I do not find the recovery section on the phone, should it be?
ABOUT . There is no longer a recovery partition on this device. Stock recovery is sewn into boot. Therefore, custom recovery can be downloaded temporarily with the "fastboot boot twrp.img" command or flashed the permanent (permanent) TWRP.zip to ramdisk from the temporary TWRP.img or installed from Magisk Manager.

AT . What is RUU and what is OTA?
ABOUT . RUU is a complete stock stock ROM firmware signed by HTC keys: ROMUpgradeUtility . Set completely, with all the phone except extSD. RUU is sewn in the current slot.
OTA, the abbreviation FOTA -FirmwareO ver T he A ir, Signed by the next update HTC stock ROM specific keys. It flies through the air on phones Sidamo. Installation does not remove user. Sewn into the other slot and after successful prshivki current slot is changed from a to b or vice versa.

AT . Do I need to close the bootloader before RUU firmware?
ABOUT . No, this is not required. For a long time on devices after HTC One M7 RUU is sewn with any bootloader status, Locked, Unlocked, Relocked.

AT . I decided to flash RUU from an extSD card, but it says in download mode that it was not found. What is the reason ?
ABOUT . First: Make sure that the external card is formatted in FAT32 or exFAT format. Second: U12 + does not see large-sized extSDs of all manufacturers. Try to swipe a card of another brand or use a 32GB card, or even less. Or use OTG (the flash drive must be formatted in exFAT format). Or use one of the RUU firmware options from a PC.

AT . Can I convert my one-character U12 + into a two-character?
ABOUT . No you can not. Any forced attempts to remake Single Sim into Dual Sim with S-ON or S-OFF and vice versa Will lead to the scorching of the phone and a trip to the SC! Single Sim can only be converted to Single Sim, and Dual Sim only to Dual Sim method with S-ON replacing CID within one MID or c S-OFF with replacing CID and MID.

AT . Another OTA has arrived, but I have the root installed. What is needed to get OTA and do I need to close the bootloader?
ABOUT . Conditions for obtaining OTA or installing it manually: a completely untouched stock system, in particular the system partition and Boot. The bootloader state (Locked, Unlocked, Relocked) does not affect the receipt of OTA. From the root, you can copy the received OTA.zip file from the folder /data/data/com.htc.updater/files on SD and share in the subject. To return to the untouched stock state, you need to flash it according to your CID, MID and software number in the Untouched Backup header (user data is not deleted). Or flash your RUU with the removal of everything on the phone, except extSD.

AT . I do not find firmware in OTA as in previous phones, only payload.bin How to get Boot.img stock?
ABOUT . U12 + is already different. There is no classic firmware in OTA, and you won’t get signed partitions from there. The header is: "How to get pristine stock Boot and System.Image, create Untouched Backup." From there, you can take it if you need to rename it to Boot.img

AT . What is an Untouched Backip Untouched System?
ABOUT . Archive created from TWRP net drain pristine System.Image and boot partitions on this phone (or collected arms and adapted to the format of the backup TWRP these sections obtained from decoding RUU or ADB commands before installing Root). Designed to recover from TWRP (or renaming of files for each separate firmware via ADB) for the removal of Ruth and return to the state of the stock for the next OTA. It is packed in zip-file only for the convenience of downloading. Restoring does not delete the user data.

AT . I want to unlock the bootloader to get the root, but the procedure goes with the factory reset. Can I backup all of my own before this?
ABOUT . Yes, on U12 + this is possible. With a temporary TWRP and at full drain with a locked bootloader, you can make data backup for subsequent recovery. Instructions in the header, full stock example .

AT . I restored my data backup and can’t log into the system with a password, it doesn’t correspond to mine.
ABOUT . The data backup was created incorrectly, you must always delete all fingers, pins, passwords, etc. before creating it. Can flash key removal script . Or manually from TWRP to delete in the file manager along the path / data / system all files locksettings. * (With various extensions). Unlike previous HTC, on U12 + the procedure is available at full 100% drain with a locked bootloader due to temporary TWRP.

AT . After restoring your data backup, some data from the internal memory, levels of some games, photo messenger, etc. were lost. How to do it right?
ABOUT . Creating data backup alone is not enough. it does not save multi-media on SD and user folders and program folders with downloads. For full recovery, do according to the instructions in the header: How to properly save / restore all your user data.

AT . Is it possible, with Ruth, get another OTA without restoration TWRP Untouched Backup and without loss of data on your phone?
ABOUT . Yes, U12 + possible. You can not return the current system in pristine condition for PTA. Suffice it to switch to another slot for OTAs. Instrkutsiya in the header.