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| Microsoft says Windows 11 update KB5079473 can cause Microsoft account sign-in failures in several apps after installation. |
It is the frustration that no Windows user wants to face on a Monday morning: you go to log into your work email, open up a crucial Excel spreadsheet, or try to save a file to OneDrive, only to be met with an error message telling you that you are offline—even though your Wi-Fi is working perfectly fine.
For many Windows 11 users who installed the latest March 2026 cumulative update, this scenario has become a frustrating reality.
Microsoft has officially confirmed a new known issue affecting systems running Windows 11 versions 24H2 and 25H2. According to the company’s updated release health documentation, the culprit is the March 2026 cumulative update KB5079473. While the update was intended to deliver security improvements and general reliability fixes as part of this month’s Patch Tuesday, it has inadvertently broken Microsoft Account sign-in functionality across a suite of essential applications.
What is KB5079473?
Released on March 10, 2026, KB5079473 is a mandatory security update for supported Windows 11 systems. It advances the OS build to 26100.8037 for Windows 11 25H2 and 26200.8037 for Windows 11 24H2.
For those looking to verify if they are affected, Microsoft maintains a detailed support page regarding the update. You can view the official release notes and build numbers directly here.
Initially, the update was viewed as a routine security sweep. However, over the last ten days, users and third-party media outlets—most notably BleepingComputer—began reporting widespread authentication failures. On March 20, 2026, Microsoft updated its Windows health dashboard to acknowledge the bug, validating what many in the tech community had suspected: this update had broken the login mechanism for Microsoft account-dependent apps.
Which Apps Are Affected?
The scope of this issue is surprisingly broad. According to reports, the error manifests when an app requires a Microsoft account sign-in to function.
Microsoft has confirmed that the following applications are currently vulnerable to the bug:
- Microsoft Teams (Free edition)
- OneDrive
- Microsoft Edge
- Excel
- Word
- Microsoft 365 Copilot
Imagine trying to access a cloud-saved document in Word, only to be told you can't because you "need the internet," despite your browser loading pages without a hitch. For freelancers, students, and enterprise workers who rely on the seamless integration of Microsoft 365, this bug has brought productivity to a screeching halt.
The "Ghost Offline" Error
Perhaps the most perplexing aspect of this issue is the nature of the error message itself. This is not a standard "wrong password" alert.
Affected devices are displaying a message that implies the computer is disconnected from the web, even when a stable internet connection is present. External media quoting Microsoft’s technical documentation describe the error text as follows:
“You’ll need the Internet for this. It doesn’t look like you’re connected to the Internet.”
It appears that KB5079473 triggers a specific network connectivity state that tricks the operating system and its applications into believing the network stack is unavailable for authentication purposes, even when other internet services remain functional.
Who Is Safe?
If you are a business user, there is a silver lining to this particular authentication nightmare. Microsoft’s release health update clarifies that the issue is isolated to consumer Microsoft accounts (such as Outlook.com, Hotmail, or personal Xbox Live accounts).
Organizations that rely on Entra ID (formerly Azure Active Directory) for app authentication are reportedly not affected by this specific problem. So, while a user might be locked out of their personal OneDrive, they may still be able to access their corporate resources without interruption.
The Workaround (And One Crucial Warning)
As of now, Microsoft has not released a permanent fix for this bug. However, the company has published a workaround that appears to reset the faulty network state.
According to the official support documentation, affected users should attempt the following:
- Ensure the device is connected to the internet (via Wi-Fi or Ethernet).
- Restart the device.
Microsoft claims that restarting while the PC is online can repair the corrupted connectivity state and prevent the issue from recurring.
However, there is a significant caveat. Microsoft warns that restarting the device without an active internet connection may return the device to the same faulty state. If you are currently experiencing this issue, ensure you have a stable connection before clicking the restart button.
Looking Ahead
KB5079473 was released as part of the March Patch Tuesday rollout, a time typically reserved for critical security fixes. While the update addressed several vulnerabilities, the introduction of this sign-in bug adds to a growing list of post-installation complaints surrounding this month’s release.
Microsoft has stated that it is working on a permanent resolution, which will likely be delivered via a future cumulative update or an "out-of-band" patch if the severity warrants an early release.
For now, if you are holding off on installing the March 2026 update, it may be wise to pause updates until Microsoft rolls out a fix. If you have already installed it and are facing the dreaded "You'll need the Internet" error while staring at a full Wi-Fi bar, a connected restart is currently your best bet to get back to work.
Source(s): Microsoft Support, BleepingComputer