URGENT – Excel 2016 copy/paste regression after KB5002934 – Version 16.0.5574.1004

Question

URGENT – Excel 2016 copy/paste regression after KB5002934 – Version 16.0.5574.1004

Árpád Bertalan 0

Dear Microsoft Support Team,

I am experiencing a serious copy/paste issue in Microsoft Excel 2016 Professional Plus following the installation of the October 2026 security update KB5002934.

The issue affects existing worksheets in important business workbooks and prevents normal daily operations.

System information:

Operating system: Windows 11, 64-bit

Microsoft Office: Professional Plus 2016, 64-bit

Installation type: MSI

Excel version: 16.0.5574.1004

MSO version: 16.0.5569.1003

Office activation status: Activated

Relevant updates:

KB5002914 – Installed September 15, 2026

KB5002934 – Installed October 14, 2026

KB5002665 – The official Microsoft installer reports that this update is already installed, although it does not appear in Windows Update history.

A similar issue occurred in September 2026 and was resolved following the removal of an update. The problem returned in October, following KB5002934.

Detailed problem description:

Copying existing cell content using Ctrl+C and Ctrl+V fails silently. The destination cell remains empty.

Copying existing worksheets also fails.

Copying the same cells into Windows Notepad works correctly.

Paste Special → Values works, but normal Excel paste does not.

Newly created Excel workbooks work correctly.

Newly created worksheets within the affected workbook also support normal copy/paste.

Newly entered values in existing worksheets can be copied successfully.

Copying existing cells into newly created worksheets still fails.

The issue persists when Excel is started in Safe Mode.

Removing conditional formatting from an affected worksheet does not resolve the problem.

Repairing the Office installation did not resolve the problem.

Rebuilding the workbook did not fully resolve the problem.

The affected business workbook contains 53 worksheets, approximately 4,839 formulas and extensive formatting. Preserving all existing formulas, worksheet relationships, formatting and print settings is essential.

Attempted update remediation:

KB5002665 was downloaded from the official Microsoft website.

Its installer reported that the update was already installed.

Attempts to remove KB5002934 using the Office update removal mechanism (Oarpmany.exe) failed.

The Excel executable remains at version 16.0.5574.1004.

Important restriction:

The current Office Professional Plus 2016 installation is activated, but the original installation media and product key are no longer available. Therefore, uninstalling or completely reinstalling Office could result in the permanent loss of a working, activated installation.

I kindly request:

Confirmation of whether KB5002934 causes a known regression affecting Excel 2016 copy/paste operations in existing worksheets.

Information about an official hotfix or updated security patch that resolves this issue.

Instructions for safely applying the correct version of KB5002665 alongside KB5002934, if applicable.

A Microsoft-supported remediation procedure that does not require uninstalling Office or losing its activation.

If no fix is available, a safe and supported workaround that preserves existing workbook functionality and security.

This issue is significantly affecting business operations. I would appreciate a concrete technical resolution rather than repeating basic Excel troubleshooting procedures, which have already been extensively completed.

Thank you for your assistance.

Kind regards

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Answer 1

Hi @Árpád Bertalan,

Thank you for raising this issue and for documenting your testing in detail.

Just to gently clarify before going any further, this is a community user-to-user forum, not official Microsoft Support. Community contributors cannot access Microsoft's internal systems, investigate potential product regressions, review diagnostic data, provide hotfixes, or escalate cases directly to the Office product team. Any confirmation of an update-related issue would need to come from Microsoft through official channels.

I recently discussed another report, KB5002665 says it’s installed, but won’t uninstall - Microsoft Q&A, which shows several similarities to your case:

Normal paste operations fail in existing Excel workbooks.
Workbooks containing conditional formatting are affected, while Paste Special remains a temporary workaround.
KB5002665 is reported as already installed when its installer is run, but it cannot be found or removed through the expected update-removal methods.
KB5002665 was installed successfully and initially addressed the earlier paste problem, but the issue returned after KB5002934 was installed again.

This closely matches your experience and suggests that KB5002934 may have reintroduced the copy/paste regression. However, Microsoft has not yet published a known issue confirming this connection, so it still requires formal investigation.

Please submit the issue through Excel > File > Feedback > Report a Problem, including the affected build numbers, installed KBs, a description of the workbook behavior.

Since Office Professional Plus 2016 is intended for organizational use and this issue is affecting business operations, your organization’s IT or licensing administrator should also open a tracked support request with Microsoft. This will allow diagnostic data to be collected and the possible regression to be escalated to the relevant product team.

Thank you so much for taking the time to read my post and share such detailed information.