Windows 11 Security Update Installation Problems Confirmed by Microsoft

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Windows 11 Security Update Install Issues Confirmed by Microsoft

Microsoft has acknowledged a known issue affecting the installation of its May 2026 security update, designated as KB5089549.

Insufficient Free Space on EFI System Partition

The issue occurs when the device has 10 megabytes or less of free space available on the EFI System Partition (ESP), resulting in the update rolling back automatically. Affected users may encounter the “Something didn’t go as planned. Undoing changes” message upon failed installation attempts.

Error Messages Indicating Insufficient ESP Free Space

SpaceCheck: Insufficient free space
ServicingBootFiles failed. Error = 0x70
SpaceCheck: used by third-party/OEM files outside of Microsoft boot directories

According to Microsoft, log entries will indicate insufficient ESP free space.

Microsoft advises affected customers to use the Known Issue Rollback feature, a Windows function that reverses buggy updates pushed via Windows Update. In enterprise-managed environments, administrators can manually mitigate the issue by installing and configuring a specific Group Policy.

Resolving the Issue through Group Policy Configuration

To resolve the issue, IT administrators must install and configure the Group Policy for their respective Windows versions. A restart is necessary to apply the group policy setting, which will temporarily disable the problematic change. For further guidance on deploying and configuring the Known Issue Rollback group policies, refer to Microsoft’s support website.

The KB5089549 update was part of a larger package released last week, addressing dozens of bugs, security patches, and improvements. Microsoft had previously resolved a separate issue causing some Windows 11 systems to boot into BitLocker recovery mode following the April 2026 security updates.

In related news, Microsoft fixed an Autopatch bug affecting driver updates restricted by administrative policies on some Autopatch-managed Windows devices within the European Union. Additionally, the company confirmed that the April 2026 security updates led to failures in third-party backup applications utilizing a vulnerable driver.