cannot paste data or formats

Dear Kevin,

Unfortunately, as a forum moderator, I am not able to inspect your machine or its update history to diagnose and fix this directly. My role here is limited to general guidance you can apply from your side. Your symptoms match a known issue introduced by the September 2026 security update for Excel 2016, KB5002914. Excel enters copy mode and shows the marching dashed border, but Paste, Paste Formats, drag and drop, and in some cases AutoFill do nothing. The fact that the same file works in LibreOffice fits this pattern, since the problem sits in Excel rather than in the Windows clipboard. This has been reported by a number of users over the past few days, including in this thread: Issue with Excel 2016 - copy and paste cells - Microsoft Q&A

To confirm the build on your machine

1. Close Excel.
2. Open Control Panel > Programs and Features.
3. Select View installed updates.
4. Search for: KB5002914
5. Check whether it was installed immediately before the problem began.

If it does not appear in that list, that does not rule it out. Several users on Windows 11 have reported that this particular update is not listed there and cannot be removed through that screen. As a second check, open Excel and go to File > Account > About Excel

For reference: Description of the security update for Excel 2016: September 08, 2026 (KB5002914).

If this computer is managed by your organization, the safest path is to raise it with your IT team, give them the KB number, and note that the problem started immediately after it was installed. They can test a rollback on one machine first and confirm Paste works again before touching anything else.

In the meantime, here are a few things that may keep you working:

• Use Excel for the web or LibreOffice for urgent work.
• Test whether Paste Special > Values still works.
• Avoid replacing Excel.exe or other Office files with older copies, because mixing Office binaries can introduce security and stability problems. 

Also, I assume "Windows 2011" means Windows 11. Please confirm that, along with the build number from the About Excel screen.

One additional consideration is that Office Professional Plus 2016 reached end of support on October 14, 2025, so Microsoft no longer guarantees technical assistance or future bug fixes for that release. Planning an upgrade to a supported Office version is recommended even if rolling back this update restores Paste.

I hope this information helps clarify the situation and provides you with workable solutions. Should you have any further questions or need additional assistance, please don't hesitate to reach out. I'm always happy to help. Have a wonderful day! 

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