Database Users

[How-To] Restore OOS from Oreo 8.1 | Restore factory encryption | Re-lock bootloader

You need to do this if you've flashed an Oreo 8.1 ROM and find that you can't get back to OOS because...
The ROM can't read /data so it hangs on the boot animation or reboots to recovery, even on a clean flash.
TWRP won't recognize your PIN/password or "default_password".
You've tried re-formatting /data from TWRP several times and it doesn't solve your problem.
Here is how to get back to 100% stock and/or restore factory encryption, which is different than Oreo 8.1 encryption:
1. Back up /sdcard to your PC as it will be erased with all of your files, pictures, music, etc.
2. Flash the stock recovery from bootloader.
Code:
fastboot flash recovery [I]stock_recovery.img[/I]
Latest OOS official stock recovery
Latest OOS beta stock recovery
3. Restore system setting in recovery.
This step is necessary to restore factory formatting and encryption of /data.
If a password/PIN is set, click “I forgot my password.”
Boot into stock recovery. Once there, go to Wipe data and cache > Reset system setting and Erase everything(Music, pics, etc.).
Note: If you don't do the "Erase everything..." option, factory encryption will not be reset.
4. Boot TWRP from bootloader.
You could flash TWRP and reboot to recovery, but TWRP will get overwritten with the stock recovery when OOS boots anyway. It's faster just to boot TWRP from a command prompt. Use the command:
Code:
fastboot boot [I]twrp-recovery.img[/I]
I recommend using using:
[RECOVERY][dumpling] TWRP 3.2.1-0 for Oreo (8.0 and 8.1) by codeworkx
5. While in TWRP, move “OOS...ROM.zip” to the SD card.
In Windows File Explorer, copy OOS...ROM.zip to the device.
Alternately, you may use the following ADB command from a command prompt
Code:
adb push [I]OOS...ROM.zip[/I] /sdcard/
Since OOS is a very large file (1.6GB), this will take 5-10 minutes.
Latest OOS signed flashable zip
Latest OOS beta (Oreo) flashable zip
6. Flash OOS...ROM.zip from TWRP.
7. Reboot system.
Your device will be formatted, encrypted and loaded with the stock recovery and ROM as it came from the factory. You may need to find the OOS...ROM.zip you pushed to /sdcard and delete it from emulated storage (/storage/emulated) if you don't see it at /sdcard after booting the ROM.
8. Optional: To re-lock your your bootloader, follow these additional steps:
This can only be done from a factory-supplied OOS ROM (including Oreo) with no modifications or the phone will not boot!
Enable USB debugging under Developer options.
Reboot to bootloader.
Unlock the bootloader with the following command:
Code:
fastboot oem lock
Return to Developer options and turn off "OEM unlocking"

Thank you for the write up .. nicely done :good:
Sent from my OnePlus5T using XDA Labs

It gave me an error 1 in TWRP. I had to do the following:
1) Make sure the bootloader remains unlocked
2) Back your apps up in TitaniumBackup
3) Back your /sdcard partition up on your computer so you don't lose anything
4) Reflash stock recovery in the bootloader
5) Boot into stock recovery and hit "forgot password" when it asks for your lock code
6) Boot back into bootloader and reflash TWRP
7) Place stock OOS zip onto the /sdcard partition
8) While you're in TWRP, flash stock recovery through its image flasher then reboot into recovery
9) Flash stock OOS, reboot, and then mod however you want
Click to expand...
Click to collapse

blackknightavalon said:
It gave me an error 1 in TWRP. I had to do the following:
Click to expand...
Click to collapse
Will in 9th last step restoring from nandroid OB-1 work ?
It should I guess
Sent from my ONEPLUS A5010 using Tapatalk

Bump!
I made a big update to the OP today with more explanation, more detail and download links.

Thanks buddy, that tutorial worked perfectly!

The other way is to flash rollback image to Nougat in stock recovery.
https://goo.gl/YRyrt6

there are no other ways to revert back to stock OOS without affecting internal sd /sdcard ?
thanks for the guide above.

Ok I'm a bit Rusty. Flash from bootloader? Meaning adb? Then adb TWRP then boot to TWRP then flash stock room(s)?

Ippolito1971 said:
Ok I'm a bit Rusty. Flash from bootloader? Meaning adb? Then adb TWRP then boot to TWRP then flash stock room(s)?
Click to expand...
Click to collapse
Please do not quote the whole OP just to get someone's attention. A mention (@the Doctor) would suffice.
To answer your question, flash the stock recovery with the fastboot command:
Code:
fastboot flash recovery [I]stock_recovery.img[/I]
The only ADB command involved is "push" to get the ROM onto the sdcard in step 5.

Thx @the Doctor. My apologies.

Thanks for the writeup, I'll probably try soon and report back.

Thanks for this, may need it. Plan to flash DU 8.1 tomorrow. So you can't just restore an ob1 or ob2 nandroid from a custom ROM?

tcat007 said:
Thanks for this, may need it. Plan to flash DU 8.1 tomorrow. So you can't just restore an ob1 or ob2 nandroid from a custom ROM?
Click to expand...
Click to collapse
You can, but TWRP will not recognize your PIN or password while in OOS, so you'll have to set lockscreen security to none or swipe. Or you could do the procedure in the OP, then restore only data from your nandroid. You'll have to re-flash Magisk or any other mods after that.

I don't use a pin for backups or restores. Since I seem to have to format internal storage to get a custom ROM to boot, was just wondering if restore of oos nandroid works once on DU.
Sent from my OnePlus5T using XDA Labs

hello thanks for the guide just did this when i boot i cant connect to any wifi network thanks

How can I get my wifi back after reverting to 4.7.6? Ive tried EFS backup and everything possible but the only way to get wifi back is to flash an Oreo zip.

forty9er said:
hello thanks for the guide just did this when i boot i cant connect to any wifi network thanks
Click to expand...
Click to collapse
Did you restore to 4.7.6 or Oreo Beta 1/2?
Dazed No More said:
How can I get my wifi back after reverting to 4.7.6? Ive tried EFS backup and everything possible but the only way to get wifi back is to flash an Oreo zip.
Click to expand...
Click to collapse
Have you flashed OOS Oreo Beta? My theory is that the firmware won't downgrade back to OOS 4.7.6, but I'm not sure. I've only restored back to OOS OB1/2, and wifi has worked perfectly every time.

the Doctor said:
Did you restore to 4.7.6 or Oreo Beta 1/2?
Have you flashed OOS Oreo Beta? My theory is that the firmware won't downgrade back to OOS 4.7.6, but I'm not sure. I've only restored back to OOS OB1/2, and wifi has worked perfectly every time.
Click to expand...
Click to collapse
Flashing Oreo beta is the only way to get it back as myself and others have found in the thread that was started on the subject. I hadn't seen that initially when I posted in here.
I was hopeful that following your method to a T would get me my wifi back on 4.7.6 but it wasn't meant to be. Absolutely nothing I have tried in the last 24 hours has worked to get it working on 4.7.6 including multiple clean and dirty flashes of the full 4.7.6 zip, twrp, stock recovery, restoring multiple backups, restoring EFS, factory reset, wipes, etc.
You might want to add that to the OP that if you revert to 4.7.6 that wifi will not work.

Dazed No More said:
You might want to add that to the OP that if you revert to 4.7.6 that wifi will not work.
Click to expand...
Click to collapse
Thank you, and done. :good:

Did i Just Brick My Phone?

I have the H910 Version.
I flashed the SuperV20 rom and the phone got stuck on the LG Screen. I pulled the battery and manually flashed Magisk. The phone still as getting stuck. So I was going to reinstall the ROM. I read that I may need an updated TWRP. I wiped my phone and went to flash and updated TWRP and when i flashed the img file i hit reboot to recovery and when it was going into recovery, the system crashed. What did i do wrong?

H0L1D4Y said:
I have the H910 Version.
I flashed the SuperV20 rom and the phone got stuck on the LG Screen. I pulled the battery and manually flashed Magisk. The phone still as getting stuck. So I was going to reinstall the ROM. I read that I may need an updated TWRP. I wiped my phone and went to flash and updated TWRP and when i flashed the img file i hit reboot to recovery and when it was going into recovery, the system crashed. What did i do wrong?
Click to expand...
Click to collapse
For safety, don't flash recovery without a working rooted rom, to keep an easy fix working.. Now since you still have the engineering bootloader, you should be able to pull the battery to get it powered down, then hold volume down while connecting to a PC to enter fastboot mode. Grab a good copy of my latest twrp . Open up a command prompt and run
Code:
fastboot flash recovery path/to/TWRP.img
. Then since your rom is broken, pull the battery after it's completed and then you should be able to get back into recovery and reflash a rom.

Password
Phoenix591 said:
For safety, don't flash recovery without a working rooted rom, to keep an easy fix working.. Now since you still have the engineering bootloader, you should be able to pull the battery to get it powered down, then hold volume down while connecting to a PC to enter fastboot mode. Grab a good copy of my latest twrp . Open up a command prompt and run
Code:
fastboot flash recovery path/to/TWRP.img
. Then since your rom is broken, pull the battery after it's completed and then you should be able to get back into recovery and reflash a rom.
Click to expand...
Click to collapse
When I open TWRP, they asked for a password so i hit cancel and did a factory reset and that fixed it. I flashed Lineage 15.1 OS and when the LG Screen loads, the phone crashes.. Should i redo the LGUP and ROOT Process?

H0L1D4Y said:
When I open TWRP, they asked for a password so i hit cancel and did a factory reset and that fixed it. I flashed Lineage 15.1 OS and when the LG Screen loads, the phone crashes.. Should i redo the LGUP and ROOT Process?
Click to expand...
Click to collapse
Did you do the regular factory reset, or did you format data? You need to format data if it was encrypted (it was if it was asking for a password in TWRP) going from anything stock based to lineage or vise versa.

Phoenix591 said:
Did you do the regular factory reset, or did you format data? You need to format data if it was encrypted (it was if it was asking for a password in TWRP) going from anything stock based to lineage or vise versa.
Click to expand...
Click to collapse
Thanks I got everything working.. I wonder why superv20 didn't work tho

H0L1D4Y said:
Thanks I got everything working.. I wonder why superv20 didn't work tho
Click to expand...
Click to collapse
Perhaps it needed the new TWRP, or perhaps it was being finicky about having something wipe or not.

switching partitions after update

I was using OOS. Switched to Lineageos. Now I'm on Havoc.
OK that's out of the way.
I installed the update today for Havoc. Went to reboot into twrp to re-root, now it's booting into the lineageos recovery. I would just use my computer to boot from twrp again, but alas I'm stuck at work
Any ideas?

aNGERY said:
I was using OOS. Switched to Lineageos. Now I'm on Havoc.
OK that's out of the way.
I installed the update today for Havoc. Went to reboot into twrp to re-root, now it's booting into the lineageos recovery. I would just use my computer to boot from twrp again, but alas I'm stuck at work
Any ideas?
Click to expand...
Click to collapse
Try switching slots. Chances are, you flashed havoc to the other slot

How do I do that?

aNGERY said:
How do I do that?
Click to expand...
Click to collapse
In recovery. When you hit reboot, at the bottom you will see A and B. Choose the other one

I don't have that option.

Oh. So you're not on an A/B device. Gotcha. Well, you may just have to clean flash then. Since you don't have to worry about a recovery partition. Because you have a dedicated recovery partition. You can't dirty flash different ROMs over each other

Delete

I'm on a 6T. I flashed the new version of Havoc on it, went to reboot afterward to install magisk, but twrp was gone. A recovery from when I tried lineageos was on the other partition, and I'm guessing it swapped to the other partition.

Just flash the rom twice so it is on A and B. Here never had a problem on my.op6 and 6t

No signal after flashing rom

Hey guys,
I recently flashed Omnirom and after doing so, noticed I had no signal. After flash, reboot, or resetting Network/Data settings, I'll have data for about 20-30 seconds. I can browse the web, but I can't send or receive calls or messages. Then it goes away completely. It sporadically returns, but drops again quickly.
Carrier is Verizon. My Sim card is still being read so the issue doesn't seem to be there. I've put it back in my Pixel 2 and it's working fine.
At a high level, this is what I've done over the past 12 hours:
1. My bootloader is unlocked. I flashed a new ROM and then it wouldn't boot.
2. I did a Factory reset through Recovery and then it booted into the ROM, where I noticed I had no signal
--Possibly an issue here? This factory reset wasn't done thru TWRP, but the stock(?) recovery. I noticed that after doing this, it wiped everything on my phone, including my Nandroid backups
3. I did another factory reset, still no service
4. I moved sim card from Sim Slot 2 to Sim slot 1, temporarily restored service. Then dropped.
5. I flashed OOS 9.0.12 back, service came back temporarily, then dropped
6. I did a network reset, restored service temporarily, then dropped
7. I reflashed modem, system, and vendor images
Anyone have any thoughts or suggestions? Otherwise, I'm probably going to send my phone back to OnePlus for repair.

Try restoring through the msm tool.

TheRemyx said:
Hey guys,
I recently flashed Omnirom and after doing so, noticed I had no signal. After flash, reboot, or resetting Network/Data settings, I'll have data for about 20-30 seconds. I can browse the web, but I can't send or receive calls or messages. Then it goes away completely. It sporadically returns, but drops again quickly.
Carrier is Verizon. My Sim card is still being read so the issue doesn't seem to be there. I've put it back in my Pixel 2 and it's working fine.
At a high level, this is what I've done over the past 12 hours:
1. My bootloader is unlocked. I flashed a new ROM and then it wouldn't boot.
2. I did a Factory reset through Recovery and then it booted into the ROM, where I noticed I had no signal
--Possibly an issue here? This factory reset wasn't done thru TWRP, but the stock(?) recovery. I noticed that after doing this, it wiped everything on my phone, including my Nandroid backups
3. I did another factory reset, still no service
4. I moved sim card from Sim Slot 2 to Sim slot 1, temporarily restored service. Then dropped.
5. I flashed OOS 9.0.12 back, service came back temporarily, then dropped
6. I did a network reset, restored service temporarily, then dropped
7. I reflashed modem, system, and vendor images
Anyone have any thoughts or suggestions? Otherwise, I'm probably going to send my phone back to OnePlus for repair.
Click to expand...
Click to collapse
Have you wiped the cache?
It's not a hardware issue.

rickysidhu_ said:
Try restoring through the msm tool.
Click to expand...
Click to collapse
I would also try the MSM tool to restore back to stock. Then reflash what you want for a ROM.

rickysidhu_ said:
Try restoring through the msm tool.
Click to expand...
Click to collapse
Scott said:
I would also try the MSM tool to restore back to stock. Then reflash what you want for a ROM.
Click to expand...
Click to collapse
Thanks guys. Using MSM worked.
For those who may have the same issue, I used MSM to go back to 9.0.11 since a few people said they had issues with 9.0.12 such as not being able to unlock it. I restored 9.0.11, unlocked my device, then flashed the 9.0.12 OTA. Issue stayed resolved.
I did try to flash Omnirom again and the issue came back, so I'm curious as to what's happening. I'm going to try another Rom.

Just an update, this seems to happen with any rom I flash now. I tried Omnirom, Pixel Experience, and Syberia OS. They boot up but with no 4g connection. When I use MSM to go back to 9.0.11 or 9.0.12 everything works properly. Not sure what I may be missing?

Out of curiosity, how are you installing your custom ROMs. I have installed quite a few custom ROMs in the last week or so and have not encountered any issues. I use a USB pendrive with an OTG adapter to install my stuff as the phone normally ends up in an encrypted state so the internal storage will not be accessible when booting into TWRP. Here are the steps I use when installing a custom ROM:
01. Boot into TWRP
02. Wipe, then swipe. You can choose to Format Data if you want, but this will erase your internal storage so you will lose your recent pictures and other media.
03. Install full OOS 9.0.11/9.0.12 depending on which version is required for the custom ROM and install TWRP also.
04. Reboot recovery.
05. Install full OOS 9.0.11/9.0.12 and TWRP again to ensure both slots have OOS install on it. Use the same version you installed in step 3.
06. Reboot recovery.
07. Install your custom ROM and TWRP.
08. Reboot recovery.
09. Wipe, then swipe (Do not format; unsure if this makes a difference).
10. Install GApps if needed (ROM dependent) and optionally install Magisk and a custom kernel.
11. Reboot system and then wait to setup the phone.
As stated, this has worked flawlessly for me and I have not run into any issues. Admittedly, I have not tried Omnirom directly, but I have tried Omnirom Treskmod (not available on XDA) and SkyDragon which are both based on Omnirom and did not have issues with either. I have tried maybe 10 different custom ROMs in the last week on so and have not had any problems. Still trying to find the best ROM for me. You could say that I'm a flashaholic.
I hope this helps.
Ooms

dj_ooms said:
Out of curiosity, how are you installing your custom ROMs. I have installed quite a few custom ROMs in the last week or so and have not encountered any issues. I use a USB pendrive with an OTG adapter to install my stuff as the phone normally ends up in an encrypted state so the internal storage will not be accessible when booting into TWRP. Here are the steps I use when installing a custom ROM:
01. Boot into TWRP
02. Wipe, then swipe. You can choose to Format Data if you want, but this will erase your internal storage so you will lose your recent pictures and other media.
03. Install full OOS 9.0.11/9.0.12 depending on which version is required for the custom ROM and install TWRP also.
04. Reboot recovery.
05. Install full OOS 9.0.11/9.0.12 and TWRP again to ensure both slots have OOS install on it. Use the same version you installed in step 3.
06. Reboot recovery.
07. Install your custom ROM and TWRP.
08. Reboot recovery.
09. Wipe, then swipe (Do not format; unsure if this makes a difference).
10. Install GApps if needed (ROM dependent) and optionally install Magisk and a custom kernel.
11. Reboot system and then wait to setup the phone.
As stated, this has worked flawlessly for me and I have not run into any issues. Admittedly, I have not tried Omnirom directly, but I have tried Omnirom Treskmod (not available on XDA) and SkyDragon which are both based on Omnirom and did not have issues with either. I have tried maybe 10 different custom ROMs in the last week on so and have not had any problems. Still trying to find the best ROM for me. You could say that I'm a flashaholic.
I hope this helps.
Ooms
Click to expand...
Click to collapse
Because I had erased all data on my phone, I was doing mostly everything from Fastboot or ADB Sideload in TWRP. So my previous steps were something like this:
1. Use MSM to restore OOS 9.0.11
2. Unlock Bootloader
3. Fastboot to TWRP 3.3.0.2
4. Install TWRP on both slots (ADB Sideload)
5. Reboot Recovery
6. Install 9.0.12 on both slots (ADB Sideload)
7. Install TWRP (ADB Sideload)
8. Reboot System to verify I have signal
9. Reboot Recovery
10. Install custom ROM and TWRP (ADB Sideload)
11. Format Data through TWRP
12. Reboot System (No signal)
I had also noticed that there was some system app or process that was repeatedly crashing, but I couldn't tell what it was because the popup notification would disappear so quickly.

TheRemyx said:
Because I had erased all data on my phone, I was doing mostly everything from Fastboot or ADB Sideload in TWRP. So my previous steps were something like this:
1. Use MSM to restore OOS 9.0.11
2. Unlock Bootloader
3. Fastboot to TWRP 3.3.0.2
4. Install TWRP on both slots (ADB Sideload)
5. Reboot Recovery
6. Install 9.0.12 on both slots (ADB Sideload)
7. Install TWRP (ADB Sideload)
8. Reboot System to verify I have signal
9. Reboot Recovery
10. Install custom ROM and TWRP (ADB Sideload)
11. Format Data through TWRP
12. Reboot System (No signal)
I had also noticed that there was some system app or process that was repeatedly crashing, but I couldn't tell what it was because the popup notification would disappear so quickly.
Click to expand...
Click to collapse
I didn't notice any popups when setting up my device. The only thing I can say is that VoLTE never used to work properly for me on OOS. I had to edit a setting in serial mode to get VoLTE working on my network in the UK. Not sure if it is related at all. I highly doubt it. I noticed in your steps, you have not flashed GApps. I believe most custom ROMs don't contain GApps, only a select few. Is there a reason you are not flashing GApps? I know there are individuals who want to stay away from Google and use Micro-G as an alternative. I believe the minimum is to flash Pico or Nano GApps. I am not sure if there is possibly something in GApps that is related to data and telephony. The notification popup you are getting may also be related to not having GApps. I install the Nano GApps so I can get face unlock working. Maybe try that and then try installing Magisk after if you still have the same issues. You are rebooting the system in your Step 12. Maybe try and reboot recovery first, then reboot system to keep TWRP intact. You could try the steps that I posted. I use a USB pendrive but if you Format Data to clear your internal storage, it should not be encrypted after unless you reboot into OOS beforehand. You should be able to push files directly to internal storage through ADB in TWRP or you can maybe mount the phone on the computer and copy the files across. These are only suggestions. I haven't had the issues you are having but the steps I listed seem to have worked consistently for my. As a note, I have never had to use the MSMTool to get my phone back up and running again. I have used fastboot mode before though.
I hope this helps.
Ooms

TheRemyx said:
Because I had erased all data on my phone, I was doing mostly everything from Fastboot or ADB Sideload in TWRP. So my previous steps were something like this:
1. Use MSM to restore OOS 9.0.11
2. Unlock Bootloader
3. Fastboot to TWRP 3.3.0.2
4. Install TWRP on both slots (ADB Sideload)
5. Reboot Recovery
6. Install 9.0.12 on both slots (ADB Sideload)
7. Install TWRP (ADB Sideload)
8. Reboot System to verify I have signal
9. Reboot Recovery
10. Install custom ROM and TWRP (ADB Sideload)
11. Format Data through TWRP
12. Reboot System (No signal)
I had also noticed that there was some system app or process that was repeatedly crashing, but I couldn't tell what it was because the popup notification would disappear so quickly.
Click to expand...
Click to collapse
Not sure if it helps, but you are doing too many repeated steps. Skip 4 & 5, Format Data before installing 9.0.12. Skip 11. Why are you installing TWRP so many times?

dj_ooms said:
I didn't notice any popups when setting up my device. The only thing I can say is that VoLTE never used to work properly for me on OOS. I had to edit a setting in serial mode to get VoLTE working on my network in the UK. Not sure if it is related at all. I highly doubt it. I noticed in your steps, you have not flashed GApps. I believe most custom ROMs don't contain GApps, only a select few. Is there a reason you are not flashing GApps? I know there are individuals who want to stay away from Google and use Micro-G as an alternative. I believe the minimum is to flash Pico or Nano GApps. I am not sure if there is possibly something in GApps that is related to data and telephony. The notification popup you are getting may also be related to not having GApps. I install the Nano GApps so I can get face unlock working. Maybe try that and then try installing Magisk after if you still have the same issues. You are rebooting the system in your Step 12. Maybe try and reboot recovery first, then reboot system to keep TWRP intact. You could try the steps that I posted. I use a USB pendrive but if you Format Data to clear your internal storage, it should not be encrypted after unless you reboot into OOS beforehand. You should be able to push files directly to internal storage through ADB in TWRP or you can maybe mount the phone on the computer and copy the files across. These are only suggestions. I haven't had the issues you are having but the steps I listed seem to have worked consistently for my. As a note, I have never had to use the MSMTool to get my phone back up and running again. I have used fastboot mode before though.
I hope this helps.
Ooms
Click to expand...
Click to collapse
I had tried flashing GAPPs (ARM64-Nano) and it didn't seem to make a difference. I was skipping that and flashing Magisk just to confirm if I had service first. But would service/signal be dependent on something in GAPPs? I may try your way. I hadn't run into any issues with encrypted storage lately. The last few times I was able to get around it by booting to system first, then rebooting back to recovery.
schmeggy929 said:
Not sure if it helps, but you are doing too many repeated steps. Skip 4 & 5, Format Data before installing 9.0.12. Skip 11. Why are you installing TWRP so many times?
Click to expand...
Click to collapse
I was installing TWRP because every time I restored or flashed, I was losing my custom recovery.

Always boot in recovery mode after an update

Hi,
I was updating my OP6T to the new version (Magisk + Xxx NoLimits), but after the reboot post-update the device started to reboot to recovery after it booted. So I've tried to delete Magisk but the problem was still present, so I've decided to download the latest Oxygen ROM from the OnePlus and flash it from TWRP, but after flashing, the device started to always boot to recovery (before the OnePlus boot animation).
At least i tried to restore a nandroid backup of 1 month ago (System, Boot and Data), but still the device after the restore still boot to recovery before the boot animation.
I've only tried the system reboot (I've not tried to force boot another slot).
Do you have a solution to try before formatting the internal storage?
Thanks
Edit: After unistalling magisk and reflashing it again, now the device boots again, but immediately after (when the lock screen appear) the device reboot automatically to recovery again

Try this:
- in twrp , dirty flash the rom you are using (Oxygen os)
- factory reset
- flash twrp (the latest the better)
- flash Magisk 19.1
Reboot to system.
If this not working, Format data will work.

null0seven said:
Try this:
- in twrp , dirty flash the rom you are using (Oxygen os)
- factory reset
- flash twrp (the latest the better)
- flash Magisk 19.1
Reboot to system.
If this not working, Format data will work.
Click to expand...
Click to collapse
Factory reset from TWRP?

yes

null0seven said:
yes
Click to expand...
Click to collapse
So, do you mean the classic Wipe data, cache and dalvik?

https://forum.xda-developers.com/oneplus-6t/how-to/official-oxygenos-9-0-4-ota-oneplus-6t-t3860953
TWRP Users
1. Boot into TWRP and Flash the Latest Magisk Uninstaller
2. Flash the latest Full Oxygen OS Zip
3. Flash the TWRP installer Zip
4. Reboot to RECOVERY to make sure TWRP stays and continue to root.
5. Flash the Latest Magisk to maintain root
6. Reboot System and Enjoy the latest firmware without any data loss
Click to expand...
Click to collapse
I am guessing you skipped the first step...
Try this:
Flash the OTA zip
Reboot (you will be unrooted and with stock recovery)
Boot to TWRP through ADB
Flash magisk unistaller
Reboot
Boot to TWRP through ADB
Flash OTA zip
Flash TWRP
Reboot to TWRP
Flash magisk

Galeanatur said:
https://forum.xda-developers.com/oneplus-6t/how-to/official-oxygenos-9-0-4-ota-oneplus-6t-t3860953
I am guessing you skipped the first step...
Try this:
Flash the OTA zip
Reboot (you will be unrooted and with stock recovery)
Boot to TWRP through ADB
Flash magisk unistaller
Reboot
Boot to TWRP through ADB
Flash OTA zip
Flash TWRP
Reboot to TWRP
Flash magisk
Click to expand...
Click to collapse
I don't have the OTA but the full rom, isn't simplier to update with the full ROM?
I think I'm going to try the null0seven's solution

null0seven said:
Try this:
- in twrp , dirty flash the rom you are using (Oxygen os)
- factory reset
- flash twrp (the latest the better)
- flash Magisk 19.1
Reboot to system.
If this not working, Format data will work.
Click to expand...
Click to collapse
Ok, I've done this and actually is even worse, the device started to boot in recovery again and TWRP doesn't recognize that the internal storage is crypted, so i can't even access the internal storage (it shows only strange folders), so, now I can't flash the nandroid backup anymore.

I also mean FULL rom .zip.
Format data in twrp or in Fastboot. Or use MSM tool .
https://forum.xda-developers.com/oneplus-6t/how-to/tool-6t-msmdownloadtool-v4-0-oos-9-0-5-t3867448
all of them will wipe ALL in youre phone, but it will work.

null0seven said:
I also mean FULL rom .zip.
Format data in twrp or in Fastboot. Or use MSM tool .
https://forum.xda-developers.com/oneplus-6t/how-to/tool-6t-msmdownloadtool-v4-0-oos-9-0-5-t3867448
all of them will wipe ALL in youre phone, but it will work.
Click to expand...
Click to collapse
So I've to Full wipe and then adb sideload the ROM? Because at the current state I can't even boot the device, it always starts in TWRP
Edit: I've also tried the blue_spark's version but nothing changed, TWRP can't recognize the encrypted storage

you can try this first.
https://forum.xda-developers.com/oneplus-6t/how-to/rom-stock-fastboot-roms-oneplus-6t-t3862516

fuji97 said:
Hi,
I was updating my OP6T to the new version (Magisk + Xxx NoLimits), but after the reboot post-update the device started to reboot to recovery after it booted. So I've tried to delete Magisk but the problem was still present, so I've decided to download the latest Oxygen ROM from the OnePlus and flash it from TWRP, but after flashing, the device started to always boot to recovery (before the OnePlus boot animation).
At least i tried to restore a nandroid backup of 1 month ago (System, Boot and Data), but still the device after the restore still boot to recovery before the boot animation.
I've only tried the system reboot (I've not tried to force boot another slot).
Do you have a solution to try before formatting the internal storage?
Thanks
Edit: After unistalling magisk and reflashing it again, now the device boots again, but immediately after (when the lock screen appear) the device reboot automatically to recovery again
Click to expand...
Click to collapse
When you're saying you're flashing the full ROM after wiping, are you meaning the xxx no limit? If so this isn't an os rom it's just a magisk module rom that's an add on to oxygen os. You need to wipe and flash the latest oxygen os rom, stable or beta which ever you're using, then flash TWRP, flash your os again on the other slot, flash TWRP, flash magisk, if your system boots fine then flash the xxx no limits rom in twrp.

ebproject said:
When you're saying you're flashing the full ROM after wiping, are you meaning the xxx no limit? If so this isn't an os rom it's just a magisk module rom that's an add on to oxygen os. You need to wipe and flash the latest oxygen os rom, stable or beta which ever you're using, then flash TWRP, flash your os again on the other slot, flash TWRP, flash magisk, if your system boots fine then flash the xxx no limits rom in twrp.
Click to expand...
Click to collapse
No, I flashed the full ROM downloaded from the OnePlus server

Have you tried formatting data?

Cablespider said:
Format data.
Click to expand...
Click to collapse
So, full format data and flash rom + TWRP + Magisk?

fuji97 said:
No, I flashed the full ROM downloaded from the OnePlus server
Click to expand...
Click to collapse
You're best bet is to use the MSM tool
https://forum.xda-developers.com/oneplus-6t/how-to/tool-6t-msmdownloadtool-v4-0-oos-9-0-5-t3867448

Ok, I've decided to use MSM to recover the device, I've lost the internal storage, but at least the device is working again.
Thank you to everyone who helped me in this thread

fuji97 said:
Ok, I've decided to use MSM to recover the device, I've lost the internal storage, but at least the device is working again.
Thank you to everyone who helped me in this thread
Click to expand...
Click to collapse
Maybe it was a Magisk module that caused it. I removed pixel module from Magisk and it done the same to me.