Windows 11 KB5095051 Breaks Office Launches via OLE Automation

Microsoft has confirmed that Windows 11 cumulative update KB5095051 introduced a known issue that can stop Microsoft Office applications from opening when launched from certain third-party programs using OLE automation. Affected apps include Word, Excel, PowerPoint, Access, and other Office components, and the failure may occur silently with no error message. Reported impacted software includes CCH Engagement, Workpaper Manager, Dentrix, Softdent, and Zotero, creating workflow disruptions for organizations that rely on Office integration from external applications.

The issue affects fully updated systems running Windows 11 version 26H1 with OS Build 28000.2269, following updates released on or after June 9. Microsoft said a fix is in progress and will be delivered in a future Windows update, while advising users to open Office apps or documents directly as a temporary workaround; enterprise customers can also contact Microsoft Support for Business for an organization-wide mitigation. Separate reporting on the same update also noted a deployment risk tied to a missing boot.STL file in installation media that can trigger boot failures with error code 0xc0430001 during dynamic update deployment.