Microsoft has announced that a subset of Windows users may have difficulties logging into their accounts via Windows Hello after installing the April 2025 security updates, specifically affecting Windows 11 24H2 and Windows Server 2025 with the KB5055523 update. The issue occurs on devices with Dynamic Root of Trust for Measurement (DRTM) or System Guard Secure Launch features enabled prior to the update. Users may see messages indicating problems with their PIN or facial recognition setup. Microsoft has provided workarounds for affected users, including re-enrollment in Windows Hello for both PIN and facial recognition. Additionally, Microsoft resolved another bug related to KB5055523 affecting Credential Guard and introduced a safeguard hold for Windows 11 24H2 systems using SenseShield Technology's sprotect.sys driver due to compatibility issues. Upgrade blocks have also been implemented for devices with incompatible software or hardware, including Dirac audio improvement software and certain applications.