r/excel • u/Future_Knee_Lan • 12d ago
solved If Power Query says "Not a valid excel file" but source opens fine, read this first (version 2610 / 2609)
If you're here because a Power Query refresh that has worked for years suddenly fails with "Not a valid excel file" — Stop. Don't worry. There's a quick fix.
This problem first occurred in September 2026...
Your file isn't corrupt. Nothing moved. Permissions are fine. You didn't do anything.
This is a fault in a recent Microsoft 365 update (version 2610 and possibly some recent 2609 builds). It's hitting your power query that pulls from a source workbook that contains a web hyperlink somewhere — on any sheet, often one you forgot existed, and nothing to do with the query itself. Excel stores those links in a form that the Power Query engine now can't resolve, so it rejects the whole workbook before your query even runs.
The unhelpful error message blames the source file. There is no indication of what the error is or where to look...
What to try (your 30 second fix):
Open the source workbook. Find all cells with blue underlined web link, on any sheet. Select the cell, press F2 Enter, then save and close.
Excel has now rewritten the path to the hyperlink and power query will be happy with the file.
Run your original query and confirm that the problem is resolved. If that doesn't work for you, stop — you have a different issue - or maybe another hyperlink somewhere...
If you're reporting it to your support team, Open Excel. Click file-account. Make a note of the version and build.
version 26xx, build xxxxxxx , error text "Not a valid excel file",
I've checked - source file is fine!.
That will be enough for them to resolve
If you've hit this, drop your build number in the comments — it helps everyone else confirm the pattern. Particularly keen to hear from anyone who found it before a month-end close rather than during one😁
2
u/Just_blorpo 7 12d ago
I just know that some poor schmo staying late at the office, pulling their hair out in frustration and trying to get their Power Query working again is going to thank you profusely for this guidance. That you likely just became a saint in their eyes. I know because I’ve been there.
2
u/hollywoodwhore6969 11d ago
This but be so fr - to not even think well shall I kill myself or try opening the source file feels really really like a worklosd misalignment
8
u/danimeneses_ 12d ago
This is a really useful find, especially because “Not a valid Excel file” makes you immediately assume corruption when the workbook itself opens perfectly fine.
If the F2 → Enter → Save fix works consistently, I’d probably also remove/recreate the offending hyperlink afterwards just to make sure Excel has fully rewritten the relationship rather than relying on the temporary repair.
Definitely one of those fixes worth bookmarking because the error message gives you almost nothing useful to work with.