Lỗi excel because the file format or file extension is not valid

Summary: This post discusses workarounds khổng lồ resolve sầu the ‘Excel cannot open the tệp tin because the extension is not valid’ error. The error may occur if you’re using an unsupported Excel file format or the file is corrupt. If the Excel tệp tin is severely corrupt, you can use an Excel repair tool lớn fix it and recover the data.Quý khách hàng đang xem: Lỗi excel cannot open the tệp tin because the tệp tin format or tệp tin extension is not valid


When opening an older version of an Excel tệp tin in a newer version, you may encounter the “Excel cannot open the file because the extension is not valid” error. This happens if you have sầu accidentally renamed the tệp tin with a different file format or an incorrect file extension. Also, you may get the ‘Excel cannot open the file’ error if the tệp tin has become unreadable or corrupted.

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This is how the complete Excel error message looks like:

“Excel cannot open the file filename.xlsx because the tệp tin format or tệp tin extension is not valid. Verify that the tệp tin has not been corrupted and that the file extension matches the format of the tệp tin.”


How to Fix ‘Excel Cannot mở cửa the File Because the Extension Is Not Valid’ Error?

Try any of these workarounds lớn fix the error and regain access to your Excel tệp tin data:

Workaround 1 – Change the Default File Format

By default, an Excel tệp tin is saved in .xlsx or .xls file format. Trying khổng lồ open the file with a different or incorrect extension may cause the ‘Excel cannot open the file because the extension is not valid’ error. To fix the error, try changing the Excel mặc định file format by following these steps:

Note: Take a backup of the Excel tệp tin that you cannot open và try the steps on the backup copy.

In Excel 2010 and newer versions, click on the File menu.

Note: For Excel 2007 & earlier versions, click on the Office button.

In Info screen that appears, clichồng on Options. In ‘Excel Options’ window, under Save workbooks section, cliông chồng on the Save sầu files in this tệp tin format: drop-down. Select a tệp tin format (i.e., the one supported by your Excel version).

Clichồng OK.

Check if you can open your Excel tệp tin. If not, try the next workaround.

Workaround 2 – Edit the Excel File Permissions

You may receive sầu the ‘Excel tệp tin format or tệp tin extension is not valid’ error if you lachồng sufficient permissions khổng lồ open the file. Usually this happens when you try to lớn open an Excel file received from some other user. Follow these steps khổng lồ change the file permissions and see if it fixes the problem:

Right-clichồng on the file that won’t open and clichồng Properties.In the file properties dialog box, click the Security tab and then hit the Edit button.

When the file’s permissions dialog box appears, cliông xã on the Add button.

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Cliông xã on the Advanced button from the ‘Select Users or Groups’ window.

Excel will các mục any unsaved files. Try opening the tệp tin & save sầu it. If this doesn’t work, skip lớn the next workaround.

Workaround 4 – Repair the Workbook

If none of the above workarounds has worked for you, chances are that the Excel file has become corrupted. Try khổng lồ repair the file using the Excel inbuilt ‘xuất hiện & Repair’ utility by following these steps:

In your Excel application, clichồng on File > Open.In the ‘Open’ dialog box that pops-up, select the Excel file you want to lớn repair & cliông xã the arrow next khổng lồ the Open button.
From the dropdown list, select xuất hiện và Repair.Excel will ask you lớn attempt to lớn repair the file or extract data from it. Click Repair lớn retrieve maximum data. If the Repair option fails, clichồng on Extract Data to lớn recover the data without formulas and values.

If the ‘xuất hiện & Repair’ utility doesn’t help fix the corrupted file and/or recover the data, use an Excel repair tool such as Stellar Repair for Excel to regain access to lớn your file và its data.

Stellar Repair for Excel software can help repair severely corrupted XLS và XLSX files. Also, it helps recover all the tệp tin components, including tables, pivot tables, cell comments, charts, chart sheets, images, formulas, etc., without impacting the original structure of the Excel file. 

To learn how the software works, read this: How khổng lồ repair corrupt Excel file using Stellar Repair for Excel?


You may encounter the error ‘Excel cannot open the tệp tin because the extension is not valid’ when opening a workbook with a different file format or an incorrect tệp tin extension. Also, the error may occur if the Excel file has turned corrupt. This article has covered some of the most effective workarounds khổng lồ resolve sầu the error. But if nothing works, you can try to repair the Excel file và retrieve sầu its data using the Stellar Repair for Excel software.


Q. I have an Excel file saved on my system. I get the error message ‘Excel cannot open the tệp tin filename.xlsx because the file format or file extension is not valid’ when trying to lớn open it. Can I get baông xã all my data using the Excel repair tool?

A. Stellar Repair for Excel displays a pnhận xét of all the recoverable data. You can get back all the Excel file data shown in the pđánh giá window.

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Q. I downloaded the repair tool, but it says, “File is severely corrupted, cannot be previewed.” What should I bởi vì next?

A. This message appears if your Excel file has turned severely corrupt. Liên hệ the support team at Stellar to get further assistance.