Microsoft confirmed that the KB5074109 January Windows 11 security update causes the classic Outlook desktop client to freeze and hang for users with POP email accounts.

Windows 11 January update is triggering black screens, Outlook crashes, and remote desktop sign-in failures, for home and enterprise users.

Microsoft’s first major Windows 11 update of 2026 quickly turned into a headache for users, after widespread reports emerged of systems failing to shut down properly and remote sign-in tools suddenly becoming unusable.

Windows 11 Patch Tuesday updates for 24H2 and 25H2 reportedly break classic Outlook, causing freezes, hangs, and lost email drafts.