Microsoft just issued emergency out of band updates for Windows 11 — but it didn't fix this bug that makes Outlook "completely unusable"

Windows 11's latest Patch Tuesday update caused two serious issues that went unspotted during Microsoft's testing. The problems were so bad that Microsoft issued emergency out of band updates for Windows 11.

One issue prevented some users from fully shutting down their PCs or signing in to a device when using Remote Desktop. Unfortunately, they are not the only issues caused by the update.

Many users of Outlook Classic are unable to open the app or use it properly when opened. One user, Chris Seagrave, posted on a Microsoft page detailing the issue:

"The first is that when I first start my laptop Outlook Classic opens, but when I close it down I am now [unable] to open it again as Office tells me it is still open. I can go into Task Manager and close the Background Process relating to Outlook Classic which allows me to open Outlook Classic again, but this is not ideal as I would rather not do this. Alternatively I can restart my laptop and Outlook Classic will open, but if I close it down it won't re-open unless I either close the Outlook Background Process in Task Manager or restart the laptop."

Outlook Classic also fails to show sent emails within the "Sent Items" folder.

User John W shared that, "Outlook classic is completely unusable since this forced windows update. Random hangs, not saving emails, etc."

The solution appears to be to uninstall the KB5074109 update. Several people saw success after reverting to a previous version of Windows 11.

Microsoft kicked off 2026 with the KB5074109, which was the first Windows 11 update of the year. That update included several fixes, including one that addressed an issue that could cause NPUs to remain powered on when the system is idle.

But with the fixes came a new set of problems. This is part of a worrying trend that got worse in 2025 and appears set to continue this year unless Microsoft makes changes to its update process.

Last year, Windows 11 users ran into bugs that caused Task Manager to fail to close and File Explorer to show a white screen when opening dark mode. A separate update broke the Windows Recovery environment.

It's normal to see headlines and social media posts about Windows 11 bugs after each Patch Tuesday update. The problems ultimately come down to a lack of robust quality control, though the specifics are more complicated.

Our Senior Editor Zac Bowden explained why frustrating bugs creep into Windows 11 at an alarming rate.

This is not the first time Outlook Classic has run into issues. Last October a bug prevented the app from opening. A separate issue causes CPU usage to spike to 50%.

The latest Outlook bug is not as serious as a problem preventing people from shutting down their PCs, but it could still break someone's workflow. Many rely on Outlook Classic for work.