Database Develop

How to root ?

Hey guys,
I just bought my Xperia Z1 model : c6903 4.3 Jelly bean version 1.4.2.A.1.136, I want to know this is work to root and how ? because I keep tried for many root program like vroot but it doesn't work even I do not know how to enter to recovery mode too. I tried to do as many way to enter to recovery mode what I have found but it doesn't work.
Thanks for your helping !

There's no way to root 4.3 directly yet. You have to downgrade to 4.2 root & install recoveries than update with custom rom.

The only way is a method to get full root on your phone. Downgrade to the firmware .534 provided by NUT to not lose IMEI, Root with Bin4ry, then follow the instruction to Update to .290 HERE, then follow the instruction to Update to .136 HERE.

First time ROOT help...urgent help!!

I was a pro Symbian firmware modder in good old Symbian days. And now migrated to android.
Thus this will be my first Android root and if succeeded I'll make and release some good CFWs.
I want to root my Z3 Compact coz some apps needs device rooted and also I dont want any restrictions.
My Z3 Compact is under warranty and I dont want to brick it nor wanna void its warranty.
I just want to Root my Z3 Compact to stock original firmware.
Currently I'm on KITKAT 4.4.4. ver. 23.0.1.A.5.77. INDIA (D5833)
Not interested for Lollypop. So please dont suggest to.
I know I have to follow the following thread:
How-to: root, keep and backup DRM keys, etc. [KitKat/Lollipops]
Still some queries before proceeding further:
In the above thread it states that,
---Downgrade the firmware, as the root exploit only works with older firmware such as 23.0.A.2.93.
So does that mean I have to downgrade below my current23.0.1.A.5.77. ?
---Downgrade fw to 23.0.A.2.93 (Device D5803) or anything prior to 23.0.1.A.5.77 (december fw)
So does this method also work on D5833) ?
---Upgrade the firmware to the latest version, while retaining root access.
So do I compulsorily have to update to any latest ver. of Kitkat or Lollipop?
I dont wanna move from my current 23.0.1.A.5.77.
---Also what is pre-rooted image and non-pre-rooted image? Which one to go for?
---Also I dont want to Unlock my Bootloader so is Rooting possible without unlocking bootloader?
---Finally I need Stock Original Sony INDIA ver 23.0.1.A.5.77 (D5833)
So where can I find it?
Answer my queries as they appear to get a clear idea.

nri_tech1183 said:
I was a pro Symbian firmware modder in good old Symbian days. And now migrated to android.
Thus this will be my first Android root and if succeeded I'll make and release some good CFWs.
I want to root my Z3 Compact coz some apps needs device rooted and also I dont want any restrictions.
My Z3 Compact is under warranty and I dont want to brick it nor wanna void its warranty.
I just want to Root my Z3 Compact to stock original firmware.
Currently I'm on KITKAT 4.4.4. ver. 23.0.1.A.5.77. INDIA (D5833)
Not interested for Lollypop. So please dont suggest to.
I know I have to follow the following thread:
How-to: root, keep and backup DRM keys, etc. [KitKat/Lollipops]
Still some queries before proceeding further:
In the above thread it states that,
---Downgrade the firmware, as the root exploit only works with older firmware such as 23.0.A.2.93.
So does that mean I have to downgrade below my current23.0.1.A.5.77. ?
---Downgrade fw to 23.0.A.2.93 (Device D5803) or anything prior to 23.0.1.A.5.77 (december fw)
So does this method also work on D5833) ?
---Upgrade the firmware to the latest version, while retaining root access.
So do I compulsorily have to update to any latest ver. of Kitkat or Lollipop?
I dont wanna move from my current 23.0.1.A.5.77.
---Also what is pre-rooted image and non-pre-rooted image? Which one to go for?
---Also I dont want to Unlock my Bootloader so is Rooting possible without unlocking bootloader?
---Finally I need Stock Original Sony INDIA ver 23.0.1.A.5.77 (D5833)
So where can I find it?
Answer my queries as they appear to get a clear idea.
Click to expand...
Click to collapse
Cannot answer everything but will try : it should work on d5833. All you need is the old firmware for the root exploid. Pre rooted image is a zip file which u can flash via recovery after u root ur current firmware and install recovery. With this u will have root from the beginning. Nearly all flashable rom have root access.
Dont know if india has some difference in firmware but u could try a pre rooted international firmware.
Unlocking bootloader is not needed for root as long as u stay on stock roms. If u want try cm12 or something else u have to unlock.
Reason for needed downgrade is the fact to backup drm keys(ta partition). Root would be easy just unlock bootloader install recovery flash su, done. But then drm keys are gone. That is the Reason for this procedure. If a general firmware wont work for u u have to download the indian firmware via xperiafirm and use prfcreator to build ur own pre rooted zip

basti2909 said:
Cannot answer everything but will try : it should work on d5833. All you need is the old firmware for the root exploid. Pre rooted image is a zip file which u can flash via recovery after u root ur current firmware and install recovery. With this u will have root from the beginning. Nearly all flashable rom have root access.
Dont know if india has some difference in firmware but u could try a pre rooted international firmware.
Unlocking bootloader is not needed for root as long as u stay on stock roms. If u want try cm12 or something else u have to unlock.
Reason for needed downgrade is the fact to backup drm keys(ta partition). Root would be easy just unlock bootloader install recovery flash su, done. But then drm keys are gone. That is the Reason for this procedure. If a general firmware wont work for u u have to download the indian firmware via xperiafirm and use prfcreator to build ur own pre rooted zip
Click to expand...
Click to collapse
Ok thanks.
So can I go ahead for root with my current kitkat 23.0.1.A.5.77 ?
...Sent from my Z3 C

Awaiting More help and replies.
...Sent from my Z3 C

@nri_tech1183
- D5833: For sure!
- Root with locked bootloader: Yep!
- Sony's stock firmwares: XperiFirm (KK or LP)
- Flashing stock firmwares: Flashtool
- Root: Downgrade to 23.0.A.2.106 fw (or older) and giefroot it (23.0.1.A.5.77 is not rootable by giefroot's exploit)!
- Utils for post root: XZDualRecovery and PRFCreator
- Pre-rooted image: Stock fw with root and/or recovery(ies)
- Non-pre-rooted image: Stock fw

Ok so once rooted can I again flash to 23.0.1.A.5.77 ???
serajr said:
@nri_tech1183
- D5833: For sure!
- Root with locked bootloader: Yep!
- Sony's stock firmwares: XperiFirm (KK or LP)
- Flashing stock firmwares: Flashtool
- Root: Downgrade to 23.0.A.2.106 fw (or older) and giefroot it (23.0.1.A.5.77 is not rootable by giefroot's exploit)!
- Utils for post root: XZDualRecovery and PRFCreator
- Pre-rooted image: Stock fw with root and/or recovery(ies)
- Non-pre-rooted image: Stock fw
Click to expand...
Click to collapse

nri_tech1183 said:
Ok so once rooted can I again flash to 23.0.1.A.5.77 ???
Click to expand...
Click to collapse
Yep, do it this way:
- Install Dual Recovery (installer)
- Create a 23.0.1.A.5.77 pre rooted firmware with Super SU and Dual Recovery
- Flash it on recovery

Guys I found another guide which allows to Root on 23.0.1.A.5.77 . http://www.ibtimes.co.uk/how-root-xperia-z3-z3-compact-locked-bootloaders-1485046
What you suggest??
I'm not able to find anyware Indian ver. of Xperia Z3 compact D5833 KITKAT ver 23.0.A.2.93.
If anybody willing to help me get it somewhere only then I'm willing to root with the method mentioned here.
Also whats the diff. between Commercial/journalist firmware and regional ones?

simplest way to root ANY smartphone without pc
1. Allow unknown sources
2. Install aptoi
3. Search in aptoide "safe remove system app"
4. Install it and run
5. It requires root and give you "root tools"
6. Install kingroot from root tools and run
7. Now you have root
P.S. In some models, from 4.3+, TB or busybox won't work. But you can use root rights for any application and uninstall unwanted pre-installed apps.
Have fun!

Ok so I decided to downgrade to good old Kitkat 4.4.4
I have the ftf file.
I dont want to root to anything but simply plain downgrade to kitkat.
Can I simply use Flashtools for downgrading?? Will my drm keys and bootloader will stay intact or will it harm??

nri_tech1183 said:
Ok so I decided to downgrade to good old Kitkat 4.4.4
I have the ftf file.
I dont want to root to anything but simply plain downgrade to kitkat.
Can I simply use Flashtools for downgrading?? Will my drm keys and bootloader will stay intact or will it harm??
Click to expand...
Click to collapse
Drm stay intact. Simple flash kitkat and u are good to go. Backup internal sd. Will be wiped

IS this method still the best for root?? Or is there any newer easy method to root without loosing drm keys and boorloader???
I want to Stock root my xperia zc d5833.
I'm on latest lollipop. Do I need to downgrade to Kitkat 4.4.4 for the root or can I root directly on existing lollipop?
What if i downgrade then how to upgrade to lollipop without loosing root???

I followed this guide and successfully rooted my z3c.
Have some very important queries:
Will a factory reset wipe the root access?
In point no. 43 you said--Open Flashtool and select the non-pre-rooted fw (this is 23.1.A.0.690), but DESELECT system: in "EXCLUDE" make sure you check the checkbox next to "SYSTEM", flash it.
So here can I flash the latest lollipop 23.4.a.0.546 fw in place of 23.1.A.0.690 ??
Can I now directly update to any latest lollipop/marshmallow via OTA/pc suite without loosing Root access?

Root Xperia Z1 5.1.1 Firmware ?

Hello People Can Any One Tell Me If Theres A Way To Root The Xperia Z1 With The Last Firmware 5.11 Without Downgrade To 5.0.2

kingroot ?

As of the moment, there are no know root procedures for 5.1.1 that have been posted in the Xperia Z1 General section other than pre-rooted FTFs downloaded using XperiFirm through Flashtool. Although - if my memory serves me right - I think I read somewhere here that if you have an unlocked bootloader, you shouldn't really have to worry about rooting as apparently it is easy to get root access. I really haven't explored the part of unlocked bootloaders even though I have a phone that I can unlock my bootloader though to be honest.

Deathschythe33 said:
As of the moment, there are no know root procedures for 5.1.1 that have been posted in the Xperia Z1 General section other than pre-rooted FTFs downloaded using XperiFirm through Flashtool. Although - if my memory serves me right - I think I read somewhere here that if you have an unlocked bootloader, you shouldn't really have to worry about rooting as apparently it is easy to get root access. I really haven't explored the part of unlocked bootloaders even though I have a phone that I can unlock my bootloader though to be honest.
Click to expand...
Click to collapse
Thank You Budy And Yes Im Right now With UNlocked BL I wish I had A Way To Root My 5.1.1 Firmware Without Going To Back To 5.0.2 And then Flash The Preerooted Version Can you Tell Me where did you read about rooting BL Unlocked

kingroot doesn't work also on 5.1.1.
im also reverting to 4.4.4 just to flash the pre-rooted 5.1.1

Salvan Malkovich said:
Thank You Budy And Yes Im Right now With UNlocked BL I wish I had A Way To Root My 5.1.1 Firmware Without Going To Back To 5.0.2 And then Flash The Preerooted Version Can you Tell Me where did you read about rooting BL Unlocked
Click to expand...
Click to collapse
Its just around the corners of Xperia Z1 General section I believe. But to be honest, I don't want to mess about with my bootloader - but that's just me, my own preference. The good thing is locked or not, we can still root our nasty Z1 phones!
If on 4.4.4 (Firmware version: 14.4.A.0.108):
Search and download
rootkitXperia_20140719.zip
Note: It is available here in our Community forums.
Use the rootkitXperia_20140719.zip to root your phone
If on 4.4.4 (Firmware version: 14.4.A.0.157):
Search and download
C690X_14.4.A.0.108_KernelOnly.ftf
C690X_14.4.A.0.157_KernelOnly.ftf
rootkitXperia_20140719.zip
Note: They are all available here in our Community forums.
Using Flashtools, flash the C690X_14.4.A.0.108_KernelOnly.ftf on your phone
Use the rootkitXperia_20140719.zip to root your phone
Then flash the C690X_14.4.A.0.157_KernelOnly.ftf back to your phone
If on 5.0.2:
Root with Kingroot
(Optional) Then replace Kingroot with SuperSU
Then install @[NUT] 's Dual XZ1 Recovery
If on 5.1.1:
Downgrade to 4.4.4 or 5.0.2 by using @Androxyde 's Flashtool
Root phone using the steps outlines above
Download a 5.1.1 FTF and create your own pre-rooted 5.1.1 Firmware, OR
Download pre-rooted Firmwares shared by our fellow community members
----
Personally though, If I have a new phone and it's on 5.1.1, I'll just downgrade to 5.0.2 because I can root it without a PC. Just use Kingroot, (optional) replace KR with SuperSU using Terminal emulator, and Baaaammm!!! phones rooted. Then I'll install DualXZ1Recovery, grab one of the pre-rooted 5.1.1, then flash away baby!!!

Deathschythe33 said:
----
Personally though, If I have a new phone and it's on 5.1.1, I'll just downgrade to 5.0.2 because I can root it without a PC. Just use Kingroot, (optional) replace KR with SuperSU using Terminal emulator, and Baaaammm!!! phones rooted. Then I'll install DualXZ1Recovery, grab one of the pre-rooted 5.1.1, then flash away baby!!!
Click to expand...
Click to collapse
I'm reverting back also to kitkat or 5.0.2 but i can't find any 5.0.2 ftf just 4.4.4.

cheeze.keyk said:
I'm reverting back also to kitkat or 5.0.2 but i can't find any 5.0.2 ftf just 4.4.4.
Click to expand...
Click to collapse
Make yourself a ftf.
Use flashtool to download your firmware. Use flashtool again to convert your firmware files to an ftf.
Flash the ftf with flashtool.
Sent from my C6903 using XDA Free mobile app

Deathschythe33 said:
Its just around the corners of Xperia Z1 General section I believe. But to be honest, I don't want to mess about with my bootloader - but that's just me, my own preference. The good thing is locked or not, we can still root our nasty Z1 phones!
If on 4.4.4 (Firmware version: 14.4.A.0.108):
Search and download
rootkitXperia_20140719.zip
Note: It is available here in our Community forums.
Use the rootkitXperia_20140719.zip to root your phone
If on 4.4.4 (Firmware version: 14.4.A.0.157):
Search and download
C690X_14.4.A.0.108_KernelOnly.ftf
C690X_14.4.A.0.157_KernelOnly.ftf
rootkitXperia_20140719.zip
Note: They are all available here in our Community forums.
Using Flashtools, flash the C690X_14.4.A.0.108_KernelOnly.ftf on your phone
Use the rootkitXperia_20140719.zip to root your phone
Then flash the C690X_14.4.A.0.157_KernelOnly.ftf back to your phone
If on 5.0.2:
Root with Kingroot
(Optional) Then replace Kingroot with SuperSU
Then install @[NUT] 's Dual XZ1 Recovery
If on 5.1.1:
Downgrade to 4.4.4 or 5.0.2 by using @Androxyde 's Flashtool
Root phone using the steps outlines above
Download a 5.1.1 FTF and create your own pre-rooted 5.1.1 Firmware, OR
Download pre-rooted Firmwares shared by our fellow community members
----
Personally though, If I have a new phone and it's on 5.1.1, I'll just downgrade to 5.0.2 because I can root it without a PC. Just use Kingroot, (optional) replace KR with SuperSU using Terminal emulator, and Baaaammm!!! phones rooted. Then I'll install DualXZ1Recovery, grab one of the pre-rooted 5.1.1, then flash away baby!!!
Click to expand...
Click to collapse
Hi, is it possible to use flashtool (im about want go back to 4.4.4 kitkat) without required root if my phone still unroot and locked BL like fresh phone?

alienx2 said:
Hi, is it possible to use flashtool (im about want go back to 4.4.4 kitkat) without required root if my phone still unroot and locked BL like fresh phone?
Click to expand...
Click to collapse
Yes.

I am new to xda and this is my first post.
I found this thread very helpful but am stock right now...I want to root my xz1 already on 5.1.1, right now I have both ftf files of 5.0.2 and 5.1.1.
My problem now is...how do I create a pre rooted 5.1.1 from the ftf file? And does installing a pre rooted firmware gives all the privileges such as installing fonts?..I'd greatly appreciate your assistance.

tipcea said:
I am new to xda and this is my first post.
I found this thread very helpful but am stock right now...I want to root my xz1 already on 5.1.1, right now I have both ftf files of 5.0.2 and 5.1.1.
My problem now is...how do I create a pre rooted 5.1.1 from the ftf file? And does installing a pre rooted firmware gives all the privileges such as installing fonts?..I'd greatly appreciate your assistance.
Click to expand...
Click to collapse
You have to use a Windows prog called PRF Creator. With it you can created your pre rooted zip file.
The pre rooted zip file will give you root privileges to your phone. With root you can basically do whatever you want.
To flash the zip you need a working custom recovery on your phone.

motorazrv3 said:
You have to use a Windows prog called PRF Creator. With it you can created your pre rooted zip file.
The pre rooted zip file will give you root privileges to your phone. With root you can basically do whatever you want.
To flash the zip you need a working custom recovery on your phone.
Click to expand...
Click to collapse
I am very grateful for this enlightenment... Will embark on it ASAP, my pc just got blind am suspecting the screen....but thanks for the quick response.

like having root in new firware 23.5.a.1.291 ?

Guys , does anyone have or know a root cause of this new way firware update 23.5.a.1.291 ? already searched and not found any post explaining how to do.
Excuse my English . by google translator

rafael.limaz said:
Guys , does anyone have or know a root cause of this new way firware update 23.5.a.1.291 ? already searched and not found any post explaining how to do.
Excuse my English . by google translator
Click to expand...
Click to collapse
If you are looking to root the new firmware I recommend checking out this guy "Gustavo RD78".
Heres a link to the thread on rooting z3 compact.
http://forum.xda-developers.com/z3-compact/development/kernel-advanced-stock-kernel-t3346328
It does require a unlocked bootloader though.
If you don't have a unlocked bootloader I don't think it is possible at the moment. I could be wrong, though.
I know KingRoot used to work on earlier version of MM, but don't think it works anymore??

Flashing old firmware(KitKat recommend, lollipop 5.0.1 can do to) and rooting with exploits.
than install XZDualRecovery.
download or make 23.5.1.A.291 pre-rooted firmware(PRF) and flashing on recovery
than you got rooted 23.5.1.A.291 firmware without unlocking bootloader

Guys - the long way back to KK is not needed anymore...
Read this (and maybe the following pages as well) ...
http://forum.xda-developers.com/showpost.php?p=68039554&postcount=138
...and download the tool from the fist page:
http://forum.xda-developers.com/showpost.php?p=67752101&postcount=1
This all means .291 FW with .575 Kernel is bootable and rootable. After Root flash only the .291 Kernel again on top.
If you are not familiar with flashtool and how to falsh single parts of an TFT FW (in this case kernel only flashing out of an TFT FW) please google and read.

A few Questions from a Noobie

Hi, im new to Note 5 Dev. and been out of the loop since it was released. i had a Sony Xperia play and a Galaxy s3 before and know how to do the basic stuff to do custom roms and flash stuff etc. to those Phones. But a Note 5 is different, running on Lollipop, having EFS partition stuff and OEM unlock Stuff. i just want to ask a few questions to make sure i don't do something stupid (i already did some of the research for answers on some of this for a few days now and some are Informative and Awesome, but a little outdated) so tnx in advance kind People :fingers-crossed:
My Device: SM-N920C (UAE)
Android Ver: 5.1.1 (Lollipop) Stock
Questions:
1.) Can i Revert back to 5.1.1 (lollipop) stock/ [Downgrade] , IF i decided to update to Nougat Stock?? (just curious ) and if yes, can you kindly link me to a process? if not, then that's fine too :laugh:
2.) Do you have to Enable OEM unlock if Updating Stock (in my case Nougat)??
I red somewhere on Magisk thread here on XDA that it can Grant Root Access to 5.0+ . If so, installing TWRP and Flashing Magisk on 5.1.1 involves Enabling USB Debugging and OEM Unlock.
3.) Do i have to Enable OEM Unlock Forever now? cause i saw some threads says that if you disable it, you will have a bootloop or a soft brick and will have to Flash Stock again and repeat. (don't really have a problem with it being Enabled, but the other people in Tutorials , Vid. Tutorials and Thread Posts just mentions "Enable it". And never really says after the process is done u can Disable it and stuff.), just want to have that information, cause i Understand that OEM is a LOCK that Even if someone steals your phone and has a lock in it. they can't just Flash a Stock Rom on it to Unlock it. [great feature] :fingers-crossed:
4.) if i have a Custom Recovery and Rooted my phone ver. 5.1.1 successfully, can i still Unroot it and go back to Stock 5.1.1?? also applies to other Versions of android. EX. nougat Stock then i root it, will i still unroot it and go back to stock?
5.) Do you need to be in a Specific Version of android to use the Custom Roms?? i mean i'm in android 5.1.1 [if rooted], can i flash a Nougat Custom Rom or a s8 port etc.?? or do i need to be in Stock Nougat > Root it > then flash Custom Nougat Roms?
That is all, Sorry if all the Questions are Freakin Long Shahaha, i just want to be specific so all the people who are also newbies can understand the questions and have answers. Tnx again for the people who have the patience to read and answer these questions. :highfive:

shadowhog006 said:
Hi, im new to Note 5 Dev. and been out of the loop since it was released. i had a Sony Xperia play and a Galaxy s3 before and know how to do the basic stuff to do custom roms and flash stuff etc. to those Phones. But a Note 5 is different, running on Lollipop, having EFS partition stuff and OEM unlock Stuff. i just want to ask a few questions to make sure i don't do something stupid (i already did some of the research for answers on some of this for a few days now and some are Informative and Awesome, but a little outdated) so tnx in advance kind People :fingers-crossed:
My Device: SM-N920C (UAE)
Android Ver: 5.1.1 (Lollipop) Stock
Questions:
1.) Can i Revert back to 5.1.1 (lollipop) stock/ [Downgrade] , IF i decided to update to Nougat Stock?? (just curious ) and if yes, can you kindly link me to a process? if not, then that's fine too :laugh:
2.) Do you have to Enable OEM unlock if Updating Stock (in my case Nougat)??
I red somewhere on Magisk thread here on XDA that it can Grant Root Access to 5.0+ . If so, installing TWRP and Flashing Magisk on 5.1.1 involves Enabling USB Debugging and OEM Unlock.
3.) Do i have to Enable OEM Unlock Forever now? cause i saw some threads says that if you disable it, you will have a bootloop or a soft brick and will have to Flash Stock again and repeat. (don't really have a problem with it being Enabled, but the other people in Tutorials , Vid. Tutorials and Thread Posts just mentions "Enable it". And never really says after the process is done u can Disable it and stuff.), just want to have that information, cause i Understand that OEM is a LOCK that Even if someone steals your phone and has a lock in it. they can't just Flash a Stock Rom on it to Unlock it. [great feature] :fingers-crossed:
4.) if i have a Custom Recovery and Rooted my phone ver. 5.1.1 successfully, can i still Unroot it and go back to Stock 5.1.1?? also applies to other Versions of android. EX. nougat Stock then i root it, will i still unroot it and go back to stock?
5.) Do you need to be in a Specific Version of android to use the Custom Roms?? i mean i'm in android 5.1.1 [if rooted], can i flash a Nougat Custom Rom or a s8 port etc.?? or do i need to be in Stock Nougat > Root it > then flash Custom Nougat Roms?
That is all, Sorry if all the Questions are Freakin Long Shahaha, i just want to be specific so all the people who are also newbies can understand the questions and have answers. Tnx again for the people who have the patience to read and answer these questions. :highfive:
Click to expand...
Click to collapse
1)If you flash stock 7.0 on your device if available then its hard to revert to back to stock 5.1.1 as there is thread in Question&Answers section about downgrading from 6.0.1 to 5.1.1 but many are unsuccessful(I have successfully downgraded from 7.0 to 6.0.1 but Cant confirm about 5.1.1 as google has changed many security policies in updates versions like 6.0.1 or 7.0 which will block your bootloader to downgrade easily/Issue you will face like lossing of baseband or corrupt imei which will block you from receiving network signal)
2)Yes its very important to enable Oem unlock and usb debugging while flashing any stock firmware using odin to avoid DM-Verity/SW Check Fail/Custom Binary blocked by FRP like issues which are hard to solve enough OR you will might hard brick your device which will be difficult to make it live again( AFAIK to flash TWRP or Any root access using odin there is instruction to enable Oem Unlock before flashing always remember it as a essential step before flashing anything using odin)
3)Yes once you enable Oem unlock for purpose of modification of your device, it needs to be unlocked or even its enabled by default to overcome reported issue like infinite bootloop or Many i mentioned in my 2nd Post And Oem unlock allows your bootloader to be customised by flashing mods or roms which is by default locked so that you could not easily modify your device as well as to avoid further modification issues
4)If you choose to stay at 5.1.1 and rooted your device with installed TWRP then yes you can unroot it by flashing 5.1.1 using odin( In case your on 6.0.1 or Even on 7.0 you can unroot your device with the same process but here to remind you that you need to flash stock 6.0.1 or 7.0 respectively version on which you rooted your device So if you will try to unroot it by flashing 5.1.1 again while your on 7.0 rooted device then again here downgrade issue which will probably give you mentioned error as a result)
5)To use custom nougat based roms or any S8+ port based on 7.0 you should atleast upgrade your bootloader and modem to 6.0.1( If your rooted on 5.1.1 and try installing nougat roms then your device will not boot as your using old bootloader, so upgrade bootloader or modem either to 6.0.1 or you can update whole system to 7.0>root>install TWRP>flash custom nougat based roms or s8+ ports afterall choice is your as if you want to upgrade only BL and Modem to 6.0.1 or want to upgrade system with BL and Modem to 7.0, i will mention here is BL and Modem for 7.0 are also available to flash you can find those on dr.ketan rom n10 installation instruction section in Samsung galaxy note 5>Android development>Dr.ketan Rom N10 instead of whole system update but Flashing Stock full firmware is always recommended for good reception and avoid glitches)
I think i have tried to fulfil all of your queries as far possible by myself
Regards,
AssassinCreed-Xda Developers

Too bad about the answer to the 3rd question, that feature would've been nice to have. but oh well. shahahaha
~Ooh!! i have a follow up question regarding your Answer to the 4th question. Can i also flash other Countries Stock firmware?? for example: mine is Stock 5.1.1 [UAE] can i flash Stock 5.1.1 [USA] or other Country variants?? [of course unlocked bootloader] , i searched again here for people who did that and for some reason they encounter Errors and Unable to revert back to their Original Stock Firmwares.
@AssassinCreed Thank you. yup, clear cut answers. Thank you!! :victory: :victory: