Message composition is also affected. If Outlook locks up while an email is being written, users can lose unsaved content and may be prompted to retype the message after the client recovers or is restarted. Even where drafts are partially retained, the interruption can break workflow and increase the risk of losing time-sensitive edits. The combination of freezing, failed restarts, and draft disruption makes the issue more than a minor annoyance for anyone who still relies on POP profiles as part of daily communication. Microsoft's current status for the issue is investigative, noting that the company is still identifying the full range of symptoms and conditions that trigger the bug.
Until a corrective update is delivered, the primary temporary workaround is to uninstall KB5074109. That approach may restore Outlook stability, but it can also remove bundled security updates, so users and administrators may need to balance reliability against patch coverage. In managed environments, a common approach is to pause or delay rollout to devices known to use POP profiles heavily, while leaving the update in place on systems not showing the regression. For now, if classic Outlook starts freezing shortly after launch, shows a white or unresponsive window, or refuses to reopen after being closed, and KB5074109 is installed, this known issue is a likely culprit. Expect more guidance once Microsoft completes its investigation and issues an updated fix through Windows Update.