New Windows 11 Emergency Patch Addresses March Optional Update Installation Error

Microsoft released another out-of-band update yesterday for Windows 11 versions 25H2 and 24H2 to address an issue preventing users from installing the March optional update (KB5079391) released on March 26. This emergency update (KB5086672) is available for Windows 11 users who have already installed the March 2026 Patch Tuesday update (KB5079473) released on March 10, or a previous emergency update (KB5085516) released on March 21 to fix sign-in issues with a Microsoft Account in Windows apps.

« While installing the March 2026 Windows preview update (KB5079391), some devices running Windows 11, version 25H2 or 24H2, might encounter the following error: Some update files are missing or have problems. We’ll try to download the update again later. Error code: (0x80073712), » Microsoft explained in the release notes for this new out-of-band update.

Microsoft had previously paused the rollout of the March optional update for Windows 11 (KB5079391) on March 27 due to this installation error. This optional update is no longer being offered to Windows 11 users, and the emergency patch released yesterday (KB5086672) includes all its new features, along with a fix for the installation issue.

We previously covered the key improvements that Windows 11 users can preview ahead of the release of the April 2026 quality update: Key additions include rich image descriptions in Narrator, the ability to toggle Smart App Control on and off without reinstalling the OS, and stability improvements when running x64 apps in the Windows Recovery Environment (WRE) on Windows 11 on Arm devices. All these new features will be rolling out gradually to Windows 11 users.