GoKawiilMicrosoft issues workaround for domain login failures tied to Machine Identity Isolation bug
Microsoft confirmed that its September security updates (KB5124008 and KB5124012) for Windows 11 are causing domain authentication failures on enterprise systems that use the Machine Identity Isolation feature. Affected devices show domain trust and credential errors even when login details are correct, because the updates cause Windows to enforce existing Machine Identity Isolation settings that are only meant for environments running Windows Server 2025 domain controllers. The company has released a temporary workaround while it develops a permanent fix.