Patch Regression: KB5002934 (October 2026) breaks copy/paste fix originally provided by KB5002665 in Excel 2016 MSI

Question

Patch Regression: KB5002934 (October 2026) breaks copy/paste fix originally provided by KB5002665 in Excel 2016 MSI

Narciso Gonzalez 10

Issue Description: The silent copy/paste failure in Excel 2016 (MSI) has returned immediately after installing the cumulative update KB5002934 (released October 13, 2026).

Technical Analysis:

Environment: Excel 2016 MSI (Traditional Volume License installer).
Build Version: EXCEL.EXE build 16.0.5574.1004.
Root Cause: The new cumulative patch KB5002934 replaces/supersedes the September hotfix KB5002665 but fails to include the clipboard regression fix. As a result, the "silent copy-paste bug" with conditional formatting has been re-introduced into the production line.
Temporary Workaround verified: Uninstalling KB5002934 and blocking it from Windows Update restores normal clipboard functionality.

Please escalate this to the Excel product development team for a hotfix re-pack.

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Paulo Neves 5 Reputation points

2026-10-17T15:30:04.11+00:00

I confirm the same situation here ... my surface updated and issue returned... same KB500002934, same regression...
Darren O'Leary 5 Reputation points

2026-10-19T03:24:26.0766667+00:00

I manage about 50+ client computers in a Windows domain for a small business and can confirm that users are experiencing the same regression since KB5002934 had been automatically installed through WIndows Update.

We are not using WSUS or any other patch management facility - just relying on the built-in Windows Update service that reaches out online to Windows Update.

Hopefully Microsoft release something soon that permanently addresses the issue.
Kamil Kisieliński 5 Reputation points

2026-10-20T11:46:32.9933333+00:00

I can confirm the regression on 10 workstations
FAVEAUX ALAIN 5 Reputation points

2026-10-20T19:18:34.0466667+00:00

Hello, we have the same issue with the copy and paste on our environment touching multiple machines since the installation of the KB5002934. We managed to block it on WSUS, but some computers already got the patch installed. Do you have a cmd or a PowerShell command that can uninstall the patch ?
Hebert Shinzato 0 Reputation points

2026-10-21T20:31:52.2833333+00:00

@FAVEAUX ALAIN I runned this command in CMD to uninstall the patch: C:\Program Files\Common Files\Microsoft Shared\OFFICE16\Oarpmany.exe /removereleaseinpatch "{90160000-0016-0000-1000-0000000FF1CE}" "{09D4430C-424A-4B29-8CE1-204B5357E1C5}" "1046" "0"But you probably need to run other command, because i runned in a PT-BR excel version.

I found the command in regedit, in this path:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall{90160000-0016-0000-1000-0000000FF1CE}Office16.EXCEL{09D4430C-424A-4B29-8CE1-204B5357E1C5}

Or try to find for "kb/5002934" in regedit and look for "UninstallString"

3 answers

Your answer

Deleted

This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
Paulo Neves 5 Reputation points

2026-10-17T15:30:04.11+00:00

I confirm the same situation here ... my surface updated and issue returned... same KB500002934, same regression...
Darren O'Leary 5 Reputation points

2026-10-19T03:24:26.0766667+00:00

I manage about 50+ client computers in a Windows domain for a small business and can confirm that users are experiencing the same regression since KB5002934 had been automatically installed through WIndows Update.

We are not using WSUS or any other patch management facility - just relying on the built-in Windows Update service that reaches out online to Windows Update.

Hopefully Microsoft release something soon that permanently addresses the issue.
Kamil Kisieliński 5 Reputation points

2026-10-20T11:46:32.9933333+00:00

I can confirm the regression on 10 workstations
FAVEAUX ALAIN 5 Reputation points

2026-10-20T19:18:34.0466667+00:00

Hello, we have the same issue with the copy and paste on our environment touching multiple machines since the installation of the KB5002934. We managed to block it on WSUS, but some computers already got the patch installed. Do you have a cmd or a PowerShell command that can uninstall the patch ?
Hebert Shinzato 0 Reputation points

2026-10-21T20:31:52.2833333+00:00

@FAVEAUX ALAIN I runned this command in CMD to uninstall the patch: C:\Program Files\Common Files\Microsoft Shared\OFFICE16\Oarpmany.exe /removereleaseinpatch "{90160000-0016-0000-1000-0000000FF1CE}" "{09D4430C-424A-4B29-8CE1-204B5357E1C5}" "1046" "0"But you probably need to run other command, because i runned in a PT-BR excel version.

I found the command in regedit, in this path:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall{90160000-0016-0000-1000-0000000FF1CE}Office16.EXCEL{09D4430C-424A-4B29-8CE1-204B5357E1C5}

Or try to find for "kb/5002934" in regedit and look for "UninstallString"

Answer 1

Hendrix 2,690 Independent Advisor

Hi Narciso,

Greatly appreciate your information. The silent paste issue was previously documented for Excel 2016 MSI after KB5002914, and Microsoft released KB5002665 on September 16 to address that issue.

KB5002934 is the October 13, 2026 security update for Excel 2016 MSI, and Microsoft documents it as replacing KB5002914. However, the currently published documentation, Description of the security update for Excel 2016: October 13, 2026 (KB5002934) | Microsoft Support, does not confirm that KB5002934 reintroduced the paste issue or that it omitted the fix from KB5002665. Since the issue began immediately after installing KB5002934 and normal functionality returned after removing it, the results provide strong evidence of a possible regression.

Therefore, I highly recommend reporting this issue to Microsoft as a suspected regression associated with KB5002934 through Excel > Help > Feedback > Report a problem. If you're using a work/school account, please ask your IT administrator to use the Report an issue option in the Microsoft 365 Admin Center > Health > Service Health to help raise visibility and provide additional diagnostic information to Microsoft. This allows them to review and acknowledge the issue, which can help prioritize a fix as soon as possible.

I will also continue to monitor the situation and keep you informed of any new information as it becomes available.

MGmirkin 5 Reputation points

2026-10-20T21:26:27.1566667+00:00

Yep, KB5002934 appears to re-enabled the copy/paste & select/drag fill failure bug.

Had borked my Excel with KB5002914. Fixed by uninstalling via command prompt since Microsoft doesn't allow simply "uninstalling" things normally anymore (boo!). Later allegedly fixed by KB5002665.

Come to find that on the 14th-ish or thereabouts Excel began exhibiting the same behavior again.

Googled it, found KB5002934 issue. No easy way to uninstall that one like the old one, via command prompt.

Had to literally restore to a previous point in time. Which, of course, failed the first time and kept rstarting saying there was a "critical service failure," so restored to an EVEN EARLIER point in time, and ran the old show/hide updates tool (which is deprecated/unsupported but still works; 'cause why let people bloody tell Windows not to reinstall the update that breaks their system?)...

Anyway, now that KB5002934 WON'T reinstall, everything is working again, and the system is back up to date, minus the re-broken update.

That said, others had the update but not the issue. Seems like maybe I ran afoul of the remaining "conditional formatting" trigger for the bug, whereas they didn't, perhaps? Anyway, things were working again after the previous two updates, but broke again after the KB5002934 update. So, ... annoying.

Definitely needs a proper fix. Bookkeeper is now running into the issue too, and i don't currently have a good fix for her, short of doing another "system restore" to prior to the re-borking update, which I'd very much prefer not to have to do, if at all possible. But may have to, since it's apparently stopping her from getting actual work done.

Why is Microsoft rolling out updates to old software that's out of support, and they say they won't update anymore, and yet they're rolling out updates that explicitly break features, in the thing they said they're not supporting/updating anymore? That's just ... annoying.

Answer 2

Hello Team,

We experienced Excel shortcut key and copy/paste issues after installing Security Update for Microsoft Excel 2016 (KB5002934) 64-Bit Edition. Systems were running Microsoft Excel 2016 Version 16.0.5574.1004. Similar reports have been raised by other organizations after installing the same update. [learn.microsoft.com], [learn.microsoft.com], [support.mi...rosoft.com]

Symptoms observed:

Ctrl+C / Ctrl+V not working correctly in existing workbooks.
Newly created workbooks function normally.
The issue is reproducible across multiple affected users.
Same workbook works correctly in newer Office versions.

Root Cause Validation:

Verified that KB5002934 was installed.
Removed the update using the Office patch removal utility.
After removing the update, the issue could no longer be reproduced.

Uninstall Command Used:

PowerShell

& "C:\Program Files\Common Files\Microsoft Shared\OFFICE16\Oarpmany.exe" /removereleaseinpatch "{90160000-0012-0000-1000-0000000FF1CE}" "{09D4430C-424A-4B29-8CE1-204B5357E1C5}" "1033" "0"

This may help administrators who are facing similar issues after deploying KB5002934.Hello Team,

We experienced Excel shortcut key and copy/paste issues after installing Security Update for Microsoft Excel 2016 (KB5002934) 64-Bit Edition. Systems were running Microsoft Excel 2016 Version 16.0.5574.1004. Similar reports have been raised by other organizations after installing the same update. [learn.microsoft.com], [learn.microsoft.com], [support.mi...rosoft.com]

Symptoms observed:

Ctrl+C / Ctrl+V not working correctly in existing workbooks.
Newly created workbooks function normally.
The issue is reproducible across multiple affected users.
Same workbook works correctly in newer Office versions.

Root Cause Validation:

Verified that KB5002934 was installed.
Removed the update using the Office patch removal utility.
After removing the update, the issue could no longer be reproduced.

Uninstall Command Used:

PowerShell as admin

& "C:\Program Files\Common Files\Microsoft Shared\OFFICE16\Oarpmany.exe" /removereleaseinpatch "{90160000-0012-0000-1000-0000000FF1CE}" "{09D4430C-424A-4B29-8CE1-204B5357E1C5}" "1033" "0"

This may help administrators who are facing similar issues after deploying KB5002934.

Regards,

Naveen Kumar Ganapathi.

Answer 3

Hendrix 2,690 Independent Advisor

Hi everyone,

Microsoft has now updated KB5002934 to build 16.0.5574.1006. This revised build fixes the known issue where paste operations could fail in Excel 2016 workbooks containing conditional formatting. For more information, please refer to Description of the security update for Excel 2016: October 13, 2026 (KB5002934) | Microsoft Support

Please install the latest revision through Windows Update or the Microsoft Update Catalog, restart the device, and confirm that the Excel version is 16.0.5574.1006 before testing again.

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