When a user opens an Excel file, it gets automatically opened without any issues. But sometimes, users are unable to open an Excel file due to an invalid extension or file format. They encounter this unexpected error with the following error message –
“Excel cannot open the file ‘filename.xlsx/.xls’ because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.”
This is how it looks –
Users are unable to open an Excel file due to one or more reasons listed below –
- File corruption
- Invalid or incorrect file extension
- Path length exceeding 218 character limit
Apart from the above reasons, some users are unable to open older Excel files (created in Excel 2000, 2003, 2007, etc.) due to incompatibility with the newer Excel versions (Excel 2013, 2016, 2019, etc.).
One or more issues mentioned above can make an Excel file inaccessible and show the unable to open the Excel file error message. This can make the data on the problematic Excel workbook inaccessible. It can also result in data loss if no prior data backup has been created.
Methods to Fix the Unable to Open an Excel File Due to an Invalid Extension Error
If you are seeing the unable to open an Excel file due to an invalid extension error message while trying to open an Excel workbook, try one or more methods explained below.
Method 1: Copy & Paste the Problematic Excel File to Another Location
The file system of Windows as set a file path character limit of 218 characters. Any file that exceeds this threshold limit shows error messages like the unable to open an Excel file due to invalid file extension or file path length.
If the Excel workbook you are trying to open is located in a subfolder that is part of a longer path, it will easily cross the path character limit. You can try and fix this by copying and pasting the Excel file to another location with less number of subfolders. Doing this should help you resolve the issue behind the unable to open an Excel file due to an invalid extension error message.
Method 2: Rename the Excel File
Renaming the excel file can also help in reducing the file path character limit. If you don’t want to move the problematic Excel workbook from its original location or changing the location didn’t fix the issue at hand, try renaming it.
Excel files that cross the file path character limit sometimes show the following error message – Windows: The File Name or Destination Path You Specified is Not Valid or Too Long.
Hence, if you are unable to open an Excel file due to invalid extension or file name, try renaming it. The steps are pretty simple –
- Right-click on the problematic Excel file and click on Rename from the context menu.
- Rename the file.
- Try opening the file again.
Method 3: Edit the Excel File Permissions
In some cases, you may receive the unable to open an Excel file due to an invalid extension error due to insufficient permissions to open it. This generally happens in cases where the file comes from another user. You can fix this error by changing the file permissions. Here is what to do –
- Right-click on the problematic Excel file.
- Click on Properties.
- Go to the Security tab and click on Edit.
- Click on Add.
- You will see the Select Users or Groups window. Click Advanced.
- Click on the Find Now button. It will generate a list of all the users and groups.
- Select Everyone from the list and click OK.
- It will return to the Select Users or Groups window. Ensure that it is displaying Everyone.
- Again, click OK.
- Choose Everyone and check all the boxes in the Permissions section.
- Click Apply and OK.
- Try opening the problematic Excel file again.
Method 4: Change the Default File Format
When you save an Excel workbook, it uses the default file formats, i:e. .xlsx or .xls to save the file. However, if you try to open a spreadsheet with an invalid or unsupported file format, it brings up the unable to open an Excel file error message. You can try to fix this error by changing the default Excel format. Here are the steps to do this –
Note – Before proceeding, take a backup of the problematic Excel file. Create a copy of it and try the below steps on the backup copy.
- Open MS Excel.
- Click on File in the Menu bar.
- Click on Options in the left panel.
- In the Excel Options window, click on Save.
- Use the drop-down menu against the Save files in this file format and choose a supported file format.
- Click OK.
- Try opening the Excel file again.
Method 5: Repair the Excel File via MS Excel’s Open & Repair Utility
If you are encountering the Unable to open an Excel file error message even after applying the above methods, then your file could be corrupted. You can repair the Excel file using MS Excel to resolve the issue. Here’s what to do –
- Open MS Excel.
- Click on File and then click on Open.
- Click on Browse and locate the corrupted Excel file.
- Select it, click on the downward arrow next to the Open button, and select the Open and Repair option.
- A dialog box will appear. Click on Repair to proceed.
- Once done, click on Close.
Note – If Excel was unable to repair the corrupt file, click on the Extract Data option. This will allow you to recover data and formulas in raw form.
Method 6: Repair the Excel File Using an Advanced Excel Repair Software
If the unable to open an Excel file error message persists even after using the Open & Repair utility of MS Excel, then it could be a case of severe file corruption. In such a scenario, try to repair the Excel file/s using a powerful Excel file repair software like Stellar Repair for Excel.
Whether your Excel workbook is corrupt, damaged, or has become inaccessible due to unsupported file format, with your Office, you can use this software to repair it. This software allows you to easily repair problematic Excel files of prominent file types like .xls, .xlsx, .xltm, .xltx, and .xlsm.
Apart from file repair, this tool helps you recover important data from a severely corrupt or unreadable Excel workbook. Finally, if you are unable to open multiple Excel files due to an invalid file extension error, use this advanced software to repair them in a single session.
Conclusion
It is not uncommon to encounter Excel-related errors while trying to access a workbook. The unable to open an Excel file due to invalid extension error occurs due to various reasons like an incompatible file format, incorrect file extension, or file corruption. This error could also occur due to longer path character length or incompatible MS Excel version.
We hope you will find the methods covered in this post helpful in resolving this error message. But if you want quick results, you can opt for an Excel recovery tool to repair the corrupted Excel file and retrieve its data quickly.
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