Microsoft has resolved a known issue that prevented Windows Server 2016 systems from successfully installing June 2026 security updates. The problem affected organizations attempting to deploy the KB5094122 update on systems that had not first installed the May 2026 KB5087537 security update, resulting in 0x80070002 or FILE_NOT_FOUND errors during installation.
The issue was confirmed through an admin portal service alert after IT administrators reported widespread installation failures. Microsoft acknowledged that the security update installation bug primarily impacted customers who had skipped the previous month's update cycle, creating a dependency chain that blocked the June update from completing successfully.
This incident is part of a broader pattern of Windows update installation problems Microsoft has addressed in recent months. In May 2026, the company fixed a similar issue causing 0x800f0922 errors during Windows 11 security update installations due to insufficient free space on the EFI System Partition. Additional problems included 0x80073712 or 0x800f0993 errors on Windows 11 24H2 and 25H2 systems, BitLocker recovery boot loops on Windows Server 2025 after April updates, and failures when using the Windows Update Standalone Installer for updates released since May 2025.
The cumulative effect of these update failures poses security risks for organizations, as delayed patching leaves systems vulnerable to known exploits. Windows Server 2016 systems that experienced the installation error remained unpatched until administrators either manually installed the prerequisite May update or waited for Microsoft's fix to deploy.
Administrators managing Windows Server 2016 environments should verify that the June 2026 KB5094122 security update has successfully installed on all systems. Organizations that previously encountered installation errors should retry the update deployment. For systems still experiencing issues, Microsoft recommends ensuring all prerequisite updates are installed in sequence. Microsoft is also currently investigating a separate issue blocking third-party applications from launching Office applications after installing June 2026 updates.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-fixes-windows-server-2016-security-update-failures/