Microsoft shares workaround for Windows domain login issues

Key Points:

• Microsoft acknowledged a login issue in Windows 11 caused by the September 2026 security updates, which enable Machine Identity Isolation enforcement and break domain trust relationships for some enterprise users.
• The problem affects users attempting to sign in with valid domain credentials, resulting in domain trust and credential errors, particularly on systems not connected to Windows Server 2025 Domain Functional Level (DFL) or higher.
• Microsoft recommends disabling Machine Identity Isolation on affected devices using the same management method it was enabled with (Intune, group policy, or registry edits) as a temporary workaround until a fix is released.
• The company is working on a future update to prevent Machine Identity Isolation enforcement from triggering these authentication issues but has not yet resolved all related problems caused by the September updates.
• Additionally, Microsoft released out-of-band patches addressing Remote Desktop, Hyper-V, and some USB audio issues from the recent updates, though some audio problems remain unresolved.