Windows 11’s latest update crashes classic Outlook and loses emails

Microsoft seems to have messed up again with its latest Windows 11 update, which borks the classic Outlook app. Earlier this month, classic Outlook struggled to open encrypted emails.

Now, Neowin reports that several users are saying the latest Windows 11 update (KB5074109) has made classic Outlook completely unusable. According to users in this Microsoft thread, classic Outlook has started to freeze randomly after the update and no longer saves emails.

However, uninstalling the KB5074109 update seems to fix the problems, as confirmed by IT company Suncoast Information Systems in the very same Microsoft support thread.

The problem doesn’t appear to be Outlook itself, but rather the way Windows is currently interacting with cloud data on OneDrive and other sources, such as Dropbox, according to Microsoft.

“For example, in some configurations of Outlook that store PST files on OneDrive, Outlook might become unresponsive and fail to reopen unless its process is terminated in Task Manager, or the system is restarted,” Microsoft says. “In addition, sent emails might not appear in the Sent Items folder, and previously downloaded might be downloaded again.”

If you still use classic Outlook and you’re running into issues after the January update for Windows 11, consider rolling back the Windows update or switching to the new Outlook app. Otherwise, Microsoft is working on a fix.

Additional reporting by Mark Hachman