Users of Windows 10 Pro and Enterprise facing an issue during upgrading from version 1511 to version 1607. After first reboot Bitlocker is causing a serious problem.
I’ve seen several queries for help from users upgrading to Windows 10 Anniversary Update (here or at reddit.com). After upgrading to version 1607, Bitlocker is asking for a recovery key after first restart. Encrypted drives could not be decrypted. Or error messages like error 0xc0210000 are dropped. I found a German blog post about this issue and a reference to this Technet forum discussion with references to TPM issues.
My MVP colleague Nils Kacencenzki has addressed this topic a few days ago at faq-o-matic.net (German articleWindows 10 Version 1607: Vorsicht mit Bitlocker!). Not it seems that Microsoft has identified the root cause and is working on a fix. During upgrade from Windows 10 Version 1511 to Version 1607, Hyper-V, DeviceGuard and Bitlocker are running in conflicts.
As a workaround has been provided by Darrell Gorter [MSFT] within this Technet forum thread.
- Keep Hyper-V disabled during OS upgrade and keep it disabled till servicing update on 8/23 comes through
- Reset the Device Guard registry keys located in HKLM\System\CurrentControlSet\Control\DeviceGuard.
- Disable Bitlocker till August 23, 2016
It seems that Microsoft plans to release a Hotfix till August 23, 2016 to address this issue.