If you have bricked your Huawei P9 lite VNS-L31 during update to nougat. you can easily recovery your phone by following this tutorial.

This tutorial applies to such phone which are stuck in erecovery mode.

Note: This guide only applies to VNS-L31 dual sim variant, if your phone is single sim you should read last paragraph first

Prepare your phone for unbricking

• Connect your phone in fastboot mode (switch off , hold volume down and connect with PC). and check if its showing phone unlocked FRP unlocked, as shown in image below

• If any of these options showing locked, then you have to unlock 1st. phon unlock (bootloader code) can be obtained by following guide posted HERE.
• FRP lock can not be removed easily, you have to contact me for FRP removal. (but its not free)

Unbricking Guide

• SD Card with atleast 8GB free space
• Download recovery file from THIS LINK  (credit @BadwolfYe & algnerd from XDA)
• Download Nougat from firmware files from THIS POST
• Copy both files to sd card  (Don’t extract them)
• Insert SD card in phone.
• Connect phone with pc in fastboot mode.
• Extract Recovery zip file, and open folder in which files are extracted, hold shift button on keyboard and right click in free space, in menu select open command prompt here.
• CMD windows will open, type ” fastboot devices ” if you see serial number of device that means connection successful otherwise reinstall drivers.
• After that type “fastboot flash recovery twrp.img” and hit enter.
• Disconnect phone from PC and boot into recovery mode (press and hold power + volume up)
• You will enter TWRP mode, swipe on 1st screen, then tap on wipe button, then select advanced wipe
• Select only data partition and tap on repair or change file system button, as shown in image below.

• on next screen select change file system, as shown in image below

• On next screen select F2FS and swipe to make changes, as shown in image below

• Repeat this process but partition type select “Ext4” and swipe to change.
• After that go back to main menu, tap on install, and select update.zip that you have copied on sd card. and swipe to install.
• On completion don’t reboot,  go back to main menu, tap on install and select other zip file update_data_full_VNS-L31_hw_eu.zip and install it.
• Don’t reboot system.

• Go back to main menu, tap on reboot and select bootloader.
• Phone should boot to fastboot mode.
• Connect it witch PC and open recovery folder that you extracted earlier
• hold shift button on keyboard and right click in free space, in menu select open command prompt here.
• CMD windows will open, type “fastboot flash recovery recovery.img” and hit enter.
• Now disconnect phone from PC, and boot into recovery mode (Volume up + Power), it will take you to stock recovery. select 2nd option wipe data/factory reset.

• once completed phone should reboot.
• phone will take like 10 minutes to boot, and you will be running Nougat.

For Single Sim version

• You can convert your phone to dual sim to install this unbrick firmware.
• Just download this DUAL sim OEM file from THIS LINK
• Copy it to sd card, and install it before install Nougat firmware file.

Note: your phone will be converted to European DUAL sim

If this method does not work CLICK HERE for new method

Special Thanks to Mr. Touseef from South Africa for screenshots, 

Information Sources :XDA forum, HTC Mania