I just had a nerve wrecking 24h period with a phone that would only boot to a BitLocker recovery screen. I hope my adventures in getting my phone back to normal can help someone out there.
Want to skip the babble? Jump to the bullet list at the bottom.
The pit of problems
I’ve been running Windows 10 Mobile on my Lumia 830 for a while, it’s a major step up from 8.1 and really nice but has some quirks. After getting a Microsoft Band 2 and experiencing some sync issues, I decided to go back to 8.1 and see if that worked better. The Windows Device Recovery Tool *should* be able to restore any phone to it’s factory state (and was recently updated to support the Lumia 950/XL etc), but I was out of luck.
First I tried to run the recovery tool on my phone as-is, the recovery tool downloaded the image but failed even before beginning the flash process. So I instead went for a reset of the phone from within the About menu. The phone rebooted to this:
Hard to read, but the screen says that the key is missing from the TPM (trusted platform module). Big bummer. On big Windows, you’re given the option to backup the encryption key (which you should do!) when activating BitLocker, but on mobile it’s a big black box. And apparently the key is impossible to obtain.
No problem for me though, I have all data and phone settings backed up to OneDrive, so just let me flash a fresh OS and start over. and we’ll be all fine. That proved to be easier said than done…
Running the recovery tool again also fails, and now I dug more into why it fails. Here’s the error message:
And examining the log show this error line:
2015-12-07 12:04:53Z | 10372 (WindowsDeviceRecoveryTool) | 0x00000019 | WindowsDeviceRecoveryTool.exe | Microsoft.WindowsDeviceRecoveryTool.Controllers.FlowController | Information | Flashing failed: Microsoft.WindowsDeviceRecoveryTool.Model.Exceptions.CheckResetProtectionException: Reading Reset Protection status Failed. phone: 1.1, ffu: at Microsoft.WindowsDeviceRecoveryTool.LumiaAdaptation.Services.Thor2Service.CheckResetProtectionStatus(Phone phone, CancellationToken cancellationToken)
Ok, something to do with reset protection status, definitely sounds BitLocker related. Digging around in the forums I found many people with the same issues, both on previous versions of the OS as well as Win10Mobile. But a lot of folks had ever found a solution, some even had taken it to several Nokia Care centers and even they weren’t able to fix it. My oh my, what to do.
Why on earth cannot the device recovery tool not just re-flash the entire thing? I don’t know.
The light at the end of the phone reboot loop
After some more digging I found references to a Lumia flashing guide at the XDA forums. I was first hesitant but decided to give it a try, and it worked! I could modify the steps a bit though since the official device recovery tool already had downloaded the correct image for my phone.
So, in brief, the steps I went for were (see the forum link above for full instructions).
- download the device recovery tool and run it
- reboot your phone (hold vol-down and power) and follow the instructions
- if you have success all the way – good for you! Close this tab now and go play.
- if you managed to get an image downloaded before fail – great! you can skip that part later
- Accept that the flash failed and head to the XDA forums
UPDATE 2016-04-01: The XDA instructions have changed, so please pay more attention to the forum page than my distilled instrutions below – but keeping them for reference.
- download the flash tools zip (link in xda forums)
- reboot in driver signature check disabled-mode and install the usb driver (found in the \driver folder of the zip)
- grab the ffu image from C:\ProgramData\Microsoft\Packages, or follow the forum instructions to obtain the correct image via a downloader tool
- reboot the phone to flash mode by holding vol-up when starting up (screen should show flash-and-gear icon)
- flash the image using the windows phone image designer (again, details as in forum instructions)
Here the beautiful screenshot of the flashing taking place:
And, now I’m staying on WinPhone 8.1 for a while longer…