Excel XLOOKUP function no longer works in Office 2024 Home

jeffersonj 30 Reputation points
2026-06-01T22:38:13.5933333+00:00

I installed Office 2024 Home on Windows 11 last year. I use Excel frequently, and XLOOKUP has worked until today (6/1/2026). However, today this function throws the #NAME? error. In cells where I had previously entered this function and saved the workbook, the formula has been changed to "=_xlfn.XLOOKUP(...)" which appears to return correct result but cannot be copied down. The file is XLSX format, and window title does NOT show "compatibility mode."

I see an update to Office (16.0.20026.20112) was installed earlier today. I suspect the failed function is related. Please fix this error or provide a reasonable solution. Thank you.

Microsoft 365 and Office | Excel | For home | Windows

Answer accepted by question author
Kai-H 27,310 Reputation points Microsoft External Staff Moderator
2026-06-02T08:27:15.04+00:00

Hi, jeffersonj

Since XLOOKUP is listed for Excel 2024, this does not look like a normal workbook compatibility problem by itself. The _xlfn. prefix usually means the copy of Excel currently opening the file is not recognizing that function, so I would first treat this as an activation/account/update issue rather than rewriting the workbook.

Here are some suggestions you can try:

Open Excel and go to File > Account. Make sure it shows the expected Office 2024 Home license and that Excel is activated. If it shows a different account, expired license, or “Product deactivated,” sign out, close Excel, reopen it, and sign back in with the Microsoft account that owns Office 2024.

Try opening the same workbook in Excel for the web through OneDrive. It is recommended that if the formula works online, save a fresh copy from there, then reopen that copy in desktop Excel. This can help confirm the workbook itself is still okay.

In the desktop file, do not manually edit every formula yet. First make a copy of the workbook. After Excel recognizes XLOOKUP again, use Find and Replace to find _xlfn. and replace it with nothing. That should restore formulas like =_xlfn.XLOOKUP(...) back to =XLOOKUP(...).

If the problem started right after build 16.0.20026.20112, report it through File > Feedback > I don’t like something and include the build number. Since Office 2024 should support XLOOKUP, this may need Microsoft to correct the update if the license is already valid.

Thank you for your patience in reading, I hope this information has been helpful to you. 


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  1. jeffersonj 30 Reputation points
    2026-06-17T21:15:16.99+00:00

    Well, surprise! While looking for specifics on updates, I had to "sign in" to my account within Excel. And suddenly XLOOKUP works fine. Causality not proven, but nothing else has changed that I know of. So I'm happy (at least till next update) and therefore will suppress a number of sarcastic remarks. And I will accept this solution.

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  2. jeffersonj 30 Reputation points
    2026-06-17T21:24:20.13+00:00

    Go to File > Account. If you see a warning message that you are not signed in, click "Sign In" button and complete sign-in process. You may need to reset your settings while you're at it.

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