Windows 11 Build 27863 Introduces Post-Quantum Security and Bug Fixes
Microsoft has released a new preview build of Windows 11 (Build 27863) to the Canary Channel. While this update isn’t packed with major features, it does include some important under-the-hood improvements — most notably, support for post-quantum cryptography , which Microsoft announced during its recent Build 2025 conference.
Specifically, Windows 11 now supports the ML-DSA post-quantum digital signature algorithm across core cryptographic APIs, including NCrypt, BCrypt , and Crypt32 certificate APIs — an early step toward future-proofing systems against quantum computing threats.
What Else Is New?
This build also brings three key fixes :
- Resolves an error (0xc0370106 ) that occurred when launching Windows Sandbox in the previous Canary build.
- Fixes an issue where core components like File Explorer and the Start menu couldn’t load in Safe Mode .
- Addresses crashes in apps like Sticky Notes and Dxdiag on systems using certain regional settings (e.g., Hebrew or Arabic), caused by issues in the msftedit.dll library.
Known Issues
- Important Note for Copilot+ PCs:
If you switch to the Canary Channel from the Dev or Release Preview Channels (or from retail), you may encounter errors (0xd0000225 ) when trying to sign in with your Windows Hello PIN or biometrics . You can fix this by re-creating your PIN via the “Set up my PIN” option. - An Administrative Templates error might appear when opening the Group Policy Editor. Clicking OK should let you continue normally. One cause has been fixed in this build, while another fix is coming soon.
- Some users report the taskbar missing acrylic effects after upgrading.
- A bug affecting audio devices with high sample rates (like 192kHz) and multiple channels is currently being investigated. Microsoft says a fix is in progress.
- Pen input may not work properly on some devices that support stylus input.
- In Task Manager , features like search and filtering are currently non-functional.