Windows 11 26H2 known issues causing upgrade nightmare

• Microsoft released Windows 11 25H2 on September 29, 2026, as a minor feature update for versions 24H2 and 25H2 users.
• The update introduces no new features, but known issues can still block or delay the upgrade on some devices.
• At the time of writing, no active upgrade-blocking issues are reported, though several problems were recently mitigated or resolved.

Microsoft released the Windows 11 2026 Update (version 26H2) on September 29, 2026. However, several known issues may still prevent some devices from upgrading or cause problems after installation.

Windows 11 26H2 is a relatively small release because it shares the same underlying platform and servicing architecture as versions 24H2 and 25H2. As a result, users upgrading from those versions aren’t getting a completely new operating system platform, but Microsoft can still introduce bugs and compatibility issues through the features and changes enabled for the new version.

Before upgrading, it’s worth checking the known issues Microsoft is tracking. The complete list is available on the Microsoft Health Dashboard.

What are the known issues on Windows 11 26H2

Here’s the list of confirmed issues blocking the upgrade to the Windows 11 2026 Update: 

• TBD

Resolved or mitigated issues

• (Mitigated) USB audio devices might fail to start or produce no sound: Some USB Audio Class 1.0 devices display Code 10 or fail in multichannel audio modes after installing the September 8 update.
• (Mitigated) Domain-joined devices might lose their secure trust relationship with the domain: Some Credential Guard protected machine accounts might be unable to sign in interactively will valid domain credentials.
• (Mitigated) Devices might experience a black screen or desktop loading issues after sign-in: Microsoft has received reports of this issue occurring in some virtual desktop environments.

If you’re planning to upgrade to version 26H2, you can use these recommendations before proceeding to avoid problems.

If a problem is identified that could negatively affect devices, the company will place a safeguard hold to prevent those devices from downloading the update until the issue has been resolved.

If you are still deciding whether to upgrade your computer now or wait, this guide will help you make an informed decision.