A significant security update from Microsoft, Windows 11 24H2 (KB5063878), is causing issues for users, making SSDs and HDDs inaccessible and potentially corrupting user data. Users have reported installation failures with error code 0x80240069, and despite a hotfix, the update has led to storage drives disappearing from the Windows environment, particularly during large sequential write operations. Recovery attempts are often unsuccessful, putting user files at risk. Microsoft has not provided an official fix, and users are advised to avoid the update and ensure routine data backups. Unplugging and reconnecting the affected drive may temporarily restore visibility but does not guarantee data safety.