A known issue caused Windows updates released since May 28, 2025 (starting with KB5058499) to fail when installed using the Windows Update Standalone Installer (WUSA) from a network share containing multiple .msu files. This affected Windows 11 versions 24H2 and 25H2, as well as Windows Server 2025, primarily in enterprise environments. The error encountered was ERROR_BAD_PATHNAME. Microsoft initially mitigated the problem on home and non-managed business devices via a Known Issue Rollback Group Policy in September 2025. The issue was fully resolved in the June 2026 Patch Tuesday cumulative updates KB5079391 for Windows 11 and KB5094125 for Windows Server 2025. Until the fix, Microsoft recommended saving .msu files locally before installation and waiting 15 minutes after installation before verifying update status.

The issue caused Windows updates to fail installation via WUSA when run from network shares with multiple .msu files, potentially disrupting patch deployment in enterprise environments using this method. It did not affect installations from single .msu files or local storage. The failure generated ERROR_BAD_PATHNAME, which could delay or prevent timely update application on affected systems.

Microsoft has officially fixed this issue in the June 2026 cumulative updates KB5079391 (Windows 11) and KB5094125 (Windows Server 2025). For systems not yet updated, a workaround is to save .msu files locally before installation. Additionally, after installing an update via WUSA, wait at least 15 minutes before checking the Update History to allow proper status reporting. No further action is required for home and non-managed business devices, as Microsoft mitigated the issue automatically via Known Issue Rollback starting September 2025.