Microsoft fixes Excel copy-and-paste failure caused by September 2026 updates

Microsoft has fixed a known issue that prevented copy and paste from working in Excel after users installed the September 2026 security updates.

The issue was reported by customers on Reddit and the Microsoft Q&A forum. The affected updates, including security update KB5002914, could also prevent Excel users from using autofill or dragging formulas.

According to Microsoft’s support documentation, the problem affected Microsoft Excel 2024, Excel 2021, Excel 2019, Excel 2016, and Excel Online in Office Online Server.

“Paste operations may fail silently in Microsoft Excel 2024, 2021, 2019, 2016, and Excel Online in Office Online Server,” Microsoft explained in documentation updated Friday.

When the bug occurs, the source cell or content remains selected while the destination remains unchanged. Excel does not display an error message or provide an audible warning that the paste operation failed.

How to fix the Excel copy-and-paste problem

Affected users must manually download and install the applicable update for their version of Office:

• Excel 2016: KB5002665
• Office LTSC 2019: build 10417.20208
• Office LTSC 2021: build 14334.20918
• Office LTSC 2024: build 17932.21000

Temporary workaround for Excel workbooks with conditional formatting

Microsoft warned that copy and paste may continue to fail when a workbook contains conditional formatting, even after the applicable update is installed.

Until a permanent fix is available for this specific scenario, Microsoft recommends using the Paste Special option as a temporary workaround.

To use it, open the Home tab, select the Paste dropdown, and choose Paste Special. Users can also press Ctrl+Alt+V to select the content they want to paste, including formulas, formulas and number formatting, values, values and number formatting, or a paste link.

Other Microsoft Office issues fixed in 2026

Earlier this year, Microsoft fixed another issue that prevented Windows 365 users from downloading the Office suite. It also resolved a problem that stopped Office on the web users from opening Excel and PowerPoint documents.

In July, Microsoft resolved an issue that prevented third-party applications from launching Microsoft Office apps such as Word, Excel, PowerPoint, and Access, or from opening documents on Windows systems.

Join Mikko Hypponen and security leaders from the NFL, Chanel, and Atlassian for a 2-hour digital summit about what will change with AI speed attacks, what defenders should stop doing, and how to verify, decide, fix, and revalidate at machine speed.

Reserve your seat