A Microsoft support document states that the company has resolved a known problem that led to copy-and-paste failures for certain Excel users following the installation of the September 2026 KB5002914 security update.

The fault caused paste operations to fail without any indication in Excel Online and in the versions of Excel 2024, 2021, 2019 and 2016, but the new fix, KB5002665, only applies to MSI-based Excel 2016.

Microsoft attributed the original issue to a code regression. A temporary workaround involving the use of Paste Special is available for the other versions affected. The fix doesn't extend to the Click-to-Run versions of Office 2016.

The problem arose after customers reported that KB5002914 caused copy-and-paste, autofill, and formula dragging to stop working in Excel. "Even when users attempt to paste content, the original source stays selected and the destination is not changed," Microsoft stated when confirming the problem and attributing it to a code regression. "In this situation, users get no sign that the operation has failed, for example no beep or error message."

Microsoft has issued update KB5002665 in order to deal with the problem. According to the support document, "this update corrects the known issue in KB5002914 which causes certain paste operations to fail silently".

Nevertheless, the remedy only covers the bug in the Microsoft Installer (.msi)-based version of Office 2016 and does not extend to the Office 2016 Click-to-Run editions, for example Microsoft Office 365 Home. Furthermore, Microsoft pointed out that some user situations affected by conditional formatting and advised customers to follow its recommendations.

People have informed BleepingComputer that the updates for Office 2019, 2021, and 2024 which were released on September 12 deal with the problem, even though Microsoft has not officially stated that these updates fix the bug.

Until a permanent fix ships for all affected versions, Microsoft advised customers to try the Paste Special option:

1. On the Home tab, choose Paste Special from the Paste drop-down menu.
2. To open the dialog press the Ctrl+Alt+V keyboard shortcut.
3. Select the following: Formula, Formula and number formats, Values, Values and number formats, or Paste Link.

Users who have been affected have also noted that copying and pasting again can be achieved by uninstalling the KB5002914 security update; however, uninstalling the update at the same time removes a long list of updates that address vulnerabilities related to remote code execution and information disclosure.

To uninstall, open Command Prompt with "Run as administrator" and run the appropriate command for the Office version:

• Office 2016 uses a program called Oarpmany.exe with the /removereleaseinpatch option.
• Office 2019 employs OfficeC2RClient.exe with the /update option and sets the user update version to 16.0.10417.20197.
• Office 2021 and 2024 use OfficeC2RClient.exe with the /update option and specify updatetoversion=16.0.20326.20132.

The fix known as KB5002665 is now available but only addresses the bug for the MSI-based version of Excel 2016, not the Click-to-Run versions.

Microsoft has not officially confirmed that a fix is available for Excel Online or for the 2019, 2021, and 2024 versions, even though users say that the September 12 updates cure the problem.

Until a permanent solution is released for all the versions affected by the issue, the only options are the Paste Special workaround or uninstalling the update, the latter option however coming at the expense of the security patches included in the update.