Microsoft has fixed Excel copy-and-paste failures caused by September 2026 updates across Office 2016, 2019, 2021, and 2024.
A September security update silently killed copy and paste, autofill and formula dragging in Excel.
Microsoft shipped an update to resolve a bug that broke copy-and-paste functionality in Excel. However, the patch is restricted to Excel 2016 and still fails on workbooks with conditional formatting.