Lost TWRP after update C100B303 to C100B307 and cannot install again

[sebbo2015]

I had a Media Pad M3 with unlocked bootloader, rooted and TWRP as recovery. As I wanted to update my ROM to BTV-DL09C100B311 I had some problems in TWRP an thought updating step by step would be a good idea. So I downloaded all missing ROMs throught FrimwareFinder and startet with BTV-DL09C100B307_fullOTA.

The installation in TWRP with ADP sideload worked and when I restartet my device a was a bit suprised that the yellow "Bootloader is unlocked - your device is unsecure" message was missing. I restarted again and the message is still missing. I thought OK perhaps I can now install all updates through the EMUI build in process without FirmwareFinder or TWRP.

EMUI downloaded the update and asked me to restart and install. After the restart the install process went to 20% and told me then there was a verification error. When I restarted the tablet again I got a screen similar to the yellow "Bootloader is unlocked - your device is unsecure". The screen is red an told me "Your device has failed verification an may not work properly".

Now I'm stuck. No updates work and TWRP could not be started or installed again.

• I tried reinstall TWRP with fasboot (https://forum.xda-developers.com/mediapad-m3/development/twrp-greatslon-mod-t3489232) but I get the error FAILED (remote: "command not allowed"). I tried the newest TWRP mod from https://androidfilehost.com/?w=files&flid=125388 but same error.
• Phone and FRP are still unlocked, as shown in FASTBOOT&RESCUE MODE so this is not the cause of the above mentioned fastboot error.
• I installed the Android SDK completly and downloaded the newest toolkit (https://developer.android.com/studio/releases/platform-tools) but still get the above error. So I dont think its a driver problem either.
• I did not try to unlock the bootloader again. I don't think this makes sense even if I still have the original codes.

I would like to get TWRP back and update the tablet to the newest ROM version. And it would also be nice to know what happened here

Thanks in advance for everyone helping me back on track. I think the first step should be get over the FAILED (remote: "command not allowed") error and install TWRP again.

 

[sebbo2015]

I got it

Needed to unlock the bootloader again. Even so it throws an error the red starting screen disappeared an I got the usual yellow one back and i could install TWRP.

//Edit

Managed to get to newest Version with this updater: https://forum.xda-developers.com/honor-9/development/tool-flash-official-firmware-recovery-t3769279

 

[Borkse]

I got it

Needed to unlock the bootloader again. Even so it throws an error the red starting screen disappeared an I got the usual yellow one back and i could install TWRP.

//Edit

Managed to get to newest Version with this updater: https://forum.xda-developers.com/honor-9/development/tool-flash-official-firmware-recovery-t3769279

I am also looking for a way to update my rooted M3 (WiFi edition) to the latest available version with security patch line of November.

Now I wonder whether with this updater in your post above this works immediately or if I also have to go through all the difficulties you faced?

Is it possible to install updates with a rooted device with this updater or do you always need to unlock the bootloader again?

Thanks for your help!

 

[Borkse]

Just tried it out now and it worked! Data is still there, homescreen icons are a little bit messed up and root is gone (no problem).

This is great because I was looking now for a long time to find a way to update a rooted M3 with new OTA updats (all the usual way fails).
I used to do it with going back to stock and a factory reset being involved.

Funny that you presented me the solution with your problem.

Glad that you shared it.

Now the only thing I am missing is to install the Xposed Framework on the M3. If you know how to do this let me know (I am using Super SU).

 

[sebbo2015]

Funny that you presented me the solution with your problem.

Glad that you shared it.

Now the only thing I am missing is to install the Xposed Framework on the M3. If you know how to do this let me know (I am using Super SU).

Im happy I could help. I dont use Xposed.

 

[kiwii.cz]

Hi, can you, please, describe this in steps? What I have to do before standard OTA update should work? And when (and how) to open bootloader once more? Thank you very much.

 

[sebbo2015]

Standard ota updates will not work. If you already have an unlocked bootloader you have to use this method https://forum.xda-developers.com/honor-9/development/tool-flash-official-firmware-recovery-t3769279 to manual update your M3 to the newest version.

If you have no unlocked bootloader please check this first https://forum.xda-developers.com/mediapad-m3/development/twrp-greatslon-mod-t3489232