Microsoft confirms Office apps launch issues after June updates

Microsoft is investigating a compatibility issue introduced by Windows updates released on or after June 9, 2026, that can prevent third‑party applications (e.g., CCH Engagement, Zotero, dental software) from launching Office apps or opening documents via OLE automation. Microsoft advises opening Office apps or documents directly as a temporary workaround, enterprise customers can contact Microsoft Support for a broader mitigation, and a fix will be delivered in a future update; there is no evidence in the report of malicious activity or security exploitation.