Excel cannot open file format or file extension is not valid.

Question

Excel cannot open the file 'Cultivate Invoice - Master.xlsx' 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 error is showing up on several of my files. How do you fix this?

Answer 1

Hi Jill,

Thank you for querying in our forum.

According to your description, it seems that you cannot open a file and encounter an error message.

It usually indicates the file is not compatible with the Excel version or the file has come corrupt or damaged. Given this situation, I want to give you suggestion below and hope that will help you:

Right click the file > Select Get Info > You can change the extension, such as xls.

If the error still occurs, I want to collect the following information for further analysis:

1. Could you provide the version of your Excel? You can go to Excel > About Excel and provide the screenshot of it.
2. May I know if all files have the same problem? You can create a new file to check if the same problem will occur.
3. May I know if this file has been stored in OneDrive for business or SharePoint Online or the local?
4. Can you open the files on Excel for Windows or Excel Online?
5. Could you provide the screenshot of error message?

Best Regards,

Sukie

Answer 2

Hi

Start by checking to make sure your copy of Office and Mac OS are compatible.

Go to the Excel menu and choose About Excel. Your version should be 16.31

Go to the Apple menu and choose About This Mac. Your version should be 10.13 or newer

Check the name of your startup volume, file names, folder names, and sheet tab names. Make sure none of these have prohibited characters such as slashes, dashes, math operators.

Make sure the file path doesn't get longer than 200 characters.

Answer 3

Hi Jill,

May I know if you still need help? If so, you can post back and we will try our best to help you.

Best Regards,

Sukie