Microsoft has confirmed a copy-and-paste issue affecting Excel 2024, 2021, 2019, and 2016 after the KB5002914 security update ...
Microsoft's September security update stops Excel from pasting. The command fails without a beep and without an error message ...
German]The Microsoft security updates released for Office applications on September 8, 2026, are causing serious collateral damage. In Excel, it is no longer possible to select and copy anything.