Excel Copy and Paste Not Working After the September 2026 Update

Current Microsoft status: Investigating

Microsoft now has a dedicated support page titled “The paste operation might fail in Excel.” The page was last updated on September 14, 2026 and lists the status as INVESTIGATING.

Microsoft’s description is unusually specific: in Excel 2024, 2021, 2019 and 2016, a user can attempt to paste content, but the source remains selected and the destination stays unchanged. Excel may provide no indication that paste failed.

That matches the confusing behavior many users are seeing after the September Office security updates: copy appears to succeed because the cells remain surrounded by the moving selection border, but pressing Ctrl+V or choosing ordinary Paste does not put the data into the target cells.

Official source: Microsoft Support — The paste operation might fail in Excel.

What the September 2026 Excel paste bug looks like

The first three behaviors are directly consistent with Microsoft’s confirmed description. Additional symptoms such as AutoFill failures, problems cancelling copied-cell selection, or particular Paste Special behavior have been reported in Microsoft Q&A threads but are not all listed on the official known-issue page.

Microsoft-confirmed behavior: known issue. Additional user reports: Microsoft Q&A.

Which Excel versions does Microsoft officially list as affected?

Microsoft’s dedicated issue page currently lists four perpetual/LTSC-style Excel generations:

• Excel 2024
• Excel 2021
• Excel 2019
• Excel 2016

This is important because community threads include reports from people who describe their installation as Microsoft 365 or Office 365. Those reports may be genuine, but Microsoft’s official known-issue page does not currently list Microsoft 365 Apps as part of the confirmed scope.

So if you use Microsoft 365, do not assume this exact bug is confirmed for your build merely because your symptom looks similar. Record the precise Excel version and build first, then compare it with Microsoft’s current support guidance.

Confirmed affected products: Microsoft Support.

What does KB5002914 have to do with the problem?

For Excel 2016, Microsoft directly lists the paste failure under the known issues for the security update released on September 8, 2026: KB5002914.

Microsoft says the Download Center package for KB5002914 applies to the Microsoft Installer (MSI) based edition of Office 2016. It does not apply to Office 2016 Click-to-Run editions such as older Microsoft 365 Home installations.

The KB page repeats the same core symptom: paste may fail silently, the source stays selected, the destination is not modified, and no warning is shown.

Official KB: KB5002914 — September 8, 2026 security update for Excel 2016.

How to check whether your problem matches Microsoft’s known issue

1. Open a new blank workbook. This helps separate the issue from workbook-specific corruption or protection.
2. Type a simple value into A1.
3. Copy A1 with Ctrl+C. Confirm that the source remains visibly selected.
4. Click B1 and press Ctrl+V.
5. Watch the destination. If B1 remains unchanged and Excel shows no error, the behavior closely matches Microsoft’s description.
6. Repeat using the ribbon or right-click Paste. This checks whether the failure is broader than the keyboard shortcut.
7. Check File → Account → About Excel and record the product name, version and build.

If copy/paste works normally in a fresh workbook but fails only in one file, investigate workbook protection, merged cells, filters, macros, add-ins, clipboard content and file-specific corruption before blaming the September update.

Try Paste Special as a temporary workaround

Microsoft’s dedicated known-issue page does not yet publish an official workaround. However, users in Microsoft Q&A threads report that Paste Special, especially values-only paste, can still work in some affected installations.

You can test it without changing your Office installation:

1. Copy the cells with Ctrl+C.
2. Click the destination.
3. Press Ctrl+Alt+V to open Paste Special.
4. Try Values first if you only need the cell contents.
5. If necessary, test other Paste Special options to see which operations remain functional on your build.

This is a community-reported workaround, not Microsoft’s final resolution. It can also change formulas, formatting, comments, validation and other cell properties depending on the option you choose, so verify the result before relying on it for important workbooks.

User reports: Microsoft Q&A — Excel Copy/Paste Issue After September 2026 Patch Tuesday Updates.

Test whether pasting from another application still works

A useful diagnostic reported in Microsoft Q&A is that copying from another application such as Notepad and pasting into Excel can still work even when copying between Excel cells fails.

That test can help separate a general Windows clipboard failure from this Excel-specific regression:

1. Open Notepad.
2. Type a simple value such as 12345.
3. Copy it.
4. Paste it into a blank Excel cell.

If external text pastes correctly but normal Excel-cell copy/paste does not, that pattern is consistent with several reports tied to the September update. It is not by itself proof of the exact bug, but it is more informative than repeatedly clearing the Windows clipboard.

Reported pattern: Microsoft Q&A.

Safe Mode can tell you whether an add-in is responsible

Launching Excel in Safe Mode is still worthwhile because it disables many add-ins and customizations. If paste starts working in Safe Mode, the September update may not be your only problem.

To test:

1. Close Excel.
2. Press Windows key + R.
3. Enter excel /safe and press Enter.
4. Open a blank workbook and repeat the basic copy/paste test.

If the same silent failure occurs in a blank workbook while Excel is in Safe Mode, an add-in becomes less likely as the sole cause. Users reporting the September regression have described testing repairs, disabled add-ins and multiple workbooks without restoring normal paste behavior.

Safe Mode is a diagnostic step, not evidence that Microsoft has published a Safe Mode workaround for the confirmed issue.

Some users also report AutoFill and fill-handle problems

Microsoft’s official paste-issue page is focused specifically on paste failing silently. It does not currently state that AutoFill is part of the confirmed bug.

However, several Microsoft Q&A reports from affected Office 2016 and Office 2021 systems also describe the fill handle or AutoFill not behaving normally after the September update.

If both paste and AutoFill stopped working immediately after the same Office patch, record both symptoms when reporting the problem. But keep the distinction clear: paste failure is Microsoft-confirmed; AutoFill is currently better described as a related community-reported symptom.

AutoFill reports: Microsoft Q&A and Office 2021 report.

Should you uninstall or roll back the September update?

Some Microsoft Q&A moderators and community responders have suggested temporarily rolling back affected Office builds, and users report that reverting to an earlier build can restore copy/paste.

But there are two reasons not to present rollback as the default permanent fix:

• The September packages are security updates. Removing them can reintroduce vulnerabilities the update was designed to address.
• Microsoft’s official known-issue page still says Investigating. Microsoft has not yet posted rollback as the universal official resolution for every affected Excel version.

For a managed business environment, rollback decisions should normally go through IT. Administrators can weigh the operational impact of broken Excel paste against the security exposure of reverting a security update, test a rollback on a limited set of machines, and prevent an automatic reinstall only for as long as necessary.

What if you use Microsoft 365 Apps?

There are user reports describing similar copy/paste failures on systems identified as Microsoft 365 or Office 365. But Microsoft’s dedicated known-issue article currently lists only Excel 2024, 2021, 2019 and 2016.

That means the safest troubleshooting path for Microsoft 365 Apps is:

1. Record the exact version, build and update channel from File → Account → About Excel.
2. Test a blank workbook.
3. Test Excel Safe Mode.
4. Check whether external text can still paste into Excel.
5. Check Microsoft’s known-issue page again to see whether the confirmed scope has expanded.
6. Use your organization’s Microsoft 365 admin/support route if the issue persists.

Do not uninstall a perpetual-license Excel update number such as KB5002914 from a Microsoft 365 Click-to-Run installation merely because the symptom looks similar.

When will Microsoft release a fix?

Microsoft has not provided a public fix date on the known-issue page reviewed on September 16, 2026. The company says the Excel team is researching the issue and will update the support article when more information becomes available.

That means any article, video or forum post claiming a specific universal fixed build should be checked against Microsoft’s support page before you install or roll back anything.

When Microsoft publishes a resolution, the most reliable next step will normally be to install the fixed Office update appropriate to your version and installation channel, then re-run the simple blank-workbook paste test.

Current resolution status: Microsoft Support.

Fast troubleshooting checklist

1. Check whether you use Excel 2024, 2021, 2019 or 2016. Those are Microsoft’s currently confirmed affected versions.
2. Record the exact Excel version and build.
3. Test copy and paste in a brand-new blank workbook.
4. Look for the confirmed pattern: source remains selected, destination stays unchanged, and no error appears.
5. Try Paste Special. It is a community-reported workaround that may work on some affected installations.
6. Try copying plain text from Notepad into Excel. If that works while Excel-to-Excel paste fails, record the result.
7. Test Excel Safe Mode. This helps rule out add-ins and customizations.
8. If you use Excel 2016 MSI, check whether KB5002914 was installed.
9. Do not assume Microsoft 365 Apps are officially included in the current affected-product list. Check the exact build.
10. Avoid casual rollback of a security update. Use IT-managed rollback only when the operational need outweighs the temporary security tradeoff.
11. Monitor Microsoft’s known-issue page for the fixed build or final resolution.