Microsoft has released a dedicated hotfix for a regression that broke copy-and-paste functionality in Excel 2016. The update, identified as KB5002665, was issued on September 16, 2026, to resolve a “silent failure” bug introduced by a security patch earlier this month.
The original issue stemmed from the September 8, 2026, security update (KB5002914). Following that installation, users reported that standard paste operations would often fail to execute. Because the failure was silent, destination cells remained unmodified without any error message or warning appearing to notify the user that the data transfer had failed.
This specific patch currently has a narrow scope. It is designed exclusively for the Windows Installer (MSI) versions of Office 2016. It does not apply to Click-to-Run installations or Microsoft 365 subscription versions of the software.
Even for users with the compatible MSI-based version, the fix carries a significant technical limitation. Microsoft has documented a “known issue” where paste operations may still fail if the workbook contains any conditional formatting. In these instances, the silent failure may persist despite the installation of the KB5002665 patch.
For users who are still experiencing the bug—either because they use a version of Office not covered by this update or because of the conditional formatting limitation—Microsoft recommends using the “Paste Special” menu as a temporary workaround. Manually selecting “Values” or “Formulas” from the special menu typically bypasses the failure that occurs during a standard keyboard shortcut or ribbon-based paste operation.
