KB5094126, KB5093998 & KB5094127 May Cause Office Apps Launch Issues from Some Third-Party Apps

Earlier this month, Microsoft released June 2026 Patch Tuesday update, KB5094126 and KB5093998, for Windows 11 version 23H2, 24H2 and 25H2. Initially, the company mentioned that there are no known issues linked with this update.

However, it has now updated the official changelog and has acknowledged a bug that might cause Microsoft Office apps fail to open from some third-party apps. The same issue may trigger for Windows 10 users who have installed the latest ESU KB5094127.

The problem affects software that relies on OLE automation, a long-standing technology used by third-party applications to communicate with Office programs like Word, Excel, PowerPoint, and Access. In some cases, users may click a file or launch command, and nothing happens at all, with no error message appearing on screen.

Microsoft says reports point to several affected applications, including CCH Engagement, Workpaper Manager, Zotero, and dental practice software such as Dentrix and Softdent. The company notes that other apps using similar integrations could also run into the same issue.

Speaking of impact, the bug appears to surface only when users attempt to open Office apps or documents from within affected third-party software. Launching Word, Excel, or other Office apps directly continues to work normally.

Microsoft is currently working on a fix and says it will be released via future Windows update. The company has not shared a timeline for the rollout.

Until then, Microsoft recommends opening Office applications or documents directly instead of launching them through third-party tools. Organizations experiencing widespread issues can also contact Microsoft Support for Business to receive an enterprise workaround. Speaking of bugs, Windows 11 KB5094126 is reportedly also causing BSODs, random freezes, and OneDrive issues for many.