Excel cannot Open the File Because the Extension is not Valid [Fix 2024]

You can get the “Excel cannot open the file because the extension is not valid” error when opening the Excel file which is incompatible with your current Excel version. There could be several other reasons behind this error. This error can occur in all versions of Microsoft Excel, including 2019. In this post, we will discuss its possible reasons and a few effective methods to fix this Excel error.

Causes of Excel cannot Open the File Because the Extension is not Valid

This error usually occurs if you’re trying to open an older version (Excel 2003)Excel file in a new Excel version (2010 or later)or vice-versa.It may also occur if the file extension is incorrect oryou may not have permission to access the file. The error can also occur if the Excel file is corrupted or damaged. Sometimes, third-party Excel add-ins can prevent you from opening the Excel file.

How to Fix ‘Excel cannot Open the File Because the Extension is not Valid’ Error?

The following methods can help you fix the error and regain Access to the Excel file.

Method 1: Change the Excel File Extension

The “Excel cannot open the file because the extension is not valid” error can occur if you try to open the Excel file with an incompatible file extension. An Excel file is saved with.XLSX or .XLS extension by default, based on the version you’re using. Excel 2007 and later versions save files in .XLSX file format, whereas Excel 2003 and earlier versions save file with.XLS extension. You can check and try changing the Excel file format. Follow the below steps:

  • In the Excel application, go to File>Options.
  • In the Excel Options window, click on the Save option under the Save Workbooks section.
  • Click on the dropdown against Save files in this format.
  • Select the compatible file format and click OK.

Method 2: Check and Change the Excel File Permissions

Insufficient file permissions can also cause the “Excel cannot open the file” error. You can try changing the Excel file permissions. Here are the steps to do so:

  • Open File Explorer.
  • Locate the desired Excel file, right-click on it, and select the Properties option.
  • In File Properties, click the Security tab, and then click the Edit option.
  • In the file’s permissions dialog box, click the Add button.
  • In the Select Users, Computers, Service Accounts, or Groups dialog box, click on the Advanced button.
  • Click Find Now. A list is displayed ofall users and groups. Choose Everyone and click OK.
  • Now, you will seethe Everyone group in the “Enter the object names to select” field. Click OK.
  • Click Everyoneinthe Group or user names field and check all the checkboxes under theAllow option.
  • Click Apply and then OK.

Method3: Check Third-Party Add-ins

You may fail to open the Excel file due to incompatible or conflicting Excel add-ins. You can check and disable the add-ins in Excel to fix the issue. Here’s how to do so:

  • First, open the Run window by pressing Windows +R.
  • In Runwindow, type excel /safe and select OK.
  • It will open the Excel application in safe mode.
  • Now, try to open the Excel file in which you are getting theerror.
  • If it opens without any error, it means add-ins are causing the error.You can check and uninstall the problematicExcel add-ins.
  • Go to the File tab and then click Options.
  • In the Excel Options dialog box, select Add-ins.
  • Under Add-ins, find and select the add-ins and select Go.
  • The Add-ins window displays the available add-ins. Unselect the add-ins and then select OK.
  • Now restart your Excel application.

Method 4: Repair your Excel File

The “Excel cannot open the file because the extension is not valid” error can occur if your Excel file becomes corrupted or unreadable. If you suspect the issue occurred due to a corrupted Excel file, you can repair it using the Excel’s inbuilt utility – Open and Repair. Here are the steps:

  • Open your Excel application.
  • Go tothe Fileoption and then click Open.
  • The Open dialog box opens up. Select the Excel file you need to repair and click the arrow next to the Open option.
  • From the dropdown option, click Open and Repair.
  • You will see a message with two options- Repair and Extract Data. Click Repair to recover as much data as possible. Click Extract Data if the Excel application fails to repair the file.

What if Nothing Works?

If the “Open and Repair” utility does not work or your file is severely corrupted, you can try third-party tools to repair the corrupt file. Stellar Repair for Excel is one such powerful and reliable excel repair tool that can help repair severely corrupted/damaged XLS/XLSX files. Also, the tool can recover all the components of Excel file, such as charts, formulas, pivot tables, etc., without changing the original formatting. The tool is compatible with all Microsoft Excel versions, including the latest 2019. You can download the software’ demo version to repair the Excel file and see its preview.


The ‘Excel cannot open the file because the extension is not valid’ error can occur if sodapdf Excel fails to read the Excel file you are trying to open. It can happen due to numerous reasons. You can try the methods mentioned in the post to fix the error. If the Excel file you are trying to open is corrupted, you can try a professional Excel repair software, such as Stellar Repair for Excel to repair your file.

About Andrew

Hey Folks! Myself Andrew Emerson I'm from Houston. I'm a blogger and writer who writes about Technology, Arts & Design, Gadgets, Movies, and Gaming etc. Hope you join me in this journey and make it a lot of fun.

Leave a Reply

Your email address will not be published. Required fields are marked *