Flashing stock Rom dies not work

Hhhhjnbggbk

Hey,
i'm trying to revert my Pixel 6 Pro back to the stock Rom. I've tried Googles web recovery, but that failed. I then downloaded the latest ota image and tried to flash with ADB sideload xxx.ZIP

Tried two images, everytime it goes up to 47% then aborts. Error messages in phone screen. What do i need to do to get it back to stock?
Errormessage on phone says "Signature Verification failed, error 21"

de0u

Hhhhjnbggbk Sideloading works only when the OTA image is signed by the same author as the OS that is running (otherwise anybody could sideload a malicious OS onto your device). So it is not possible to sideload Google's OS on top of GrapheneOS.

What steps were taken to revert the device to the stock OS? Was the GrapheneOS signing key removed?

Hhhhjnbggbk

de0u
Forgot to mention, yes i did that.

fastboot erase avb_custom_key

Apart from that i've tried wiping the phone from the sideloader menu. That also gave some error messages "unable to enable exr4 verity...."

GrapheneOS still boots fine

Hhhhjnbggbk

This was my devices Screen output

https://i.postimg.cc/85RgWNwy/GOS-Klein.jpg

de0u

Hhhhjnbggbk I believe I have seen that error message during factory reset and I don't believe it's a problem.

Sideloading a Google OTA image on top of GrapheneOS will not work ever. To return to the stock OS it will be necessary to unlock the bootloader and flash the stock OS, using Google's web installer or via the command line.

Hhhhjnbggbk

de0u
The web installer does not work.
Gould you point me to the neccessary commandline commands? I've just found the commandline for sideloading in the psge where i can download the original OTA Images.

Skyway

Hhhhjnbggbk why won't the Google web installer work?
I've used it many times.

de0u

Hhhhjnbggbk Gould you point me to the neccessary commandline commands

https://source.android.com/docs/setup/test/running

Hhhhjnbggbk

Skyway
The google Webinstaller/recovery starts, wiping the phone works, downloading the image works, flashing to the phone starts , runs for a minute or so, then it stops when the progress bar hits 30% or so ....
It gives no reason, just says "failed" and a button to try again.

I've also tried to re-flash the latest GrapheneOS image with the GrapheneOS webinstaller... This works.

Hhhhjnbggbk

de0u
Thank you!
I'll give it a try.

de0u

Hhhhjnbggbk The google Webinstaller/recovery starts, wiping the phone works, downloading the image works, flashing to the phone starts , runs for a minute or so, then it stops when the progress bar hits 30% or so ....

It's hard to say what is causing that, but it is consistent with a bad cable.

Hhhhjnbggbk

de0u never had issues with the cable that i've used, but i'll try another one. Thanks!