Solution 7: Open MS Excel in Safe Mode Solving the “ Excel cannot open because the file format is not valid ” problem can sometimes be as simple as booting your computer into Safe Mode . This is ...

Every now and then, when I try opening an Excel file, I get a message saying that "Excel cannot open the file 'file.xlsx' because the file format or the file extension is not valid.

With the Excel extension is not valid error, try starting the app in Safe Mode, repair the workbook or open the file in another program.

To fix the Excel file format does not match extension error, trying opening the spreadsheet with the Open and Repair option or changing its file extension.

For those cautious about third-party software, LibreOffice is a free and open-source alternative that supports various file types. If the file opens in LibreOffice, save a duplicate, which will then ...

excel cannot open the file because the file format or file extension is not valid #357 Open janjaw007 opened on Feb 12, 2024 ...

Greetings, I have a user who was working on an Excel 2007 file from a thumbdrive.. all of a suddem the file will not open and generates the following error: "Excel cannot open the file 'filename.xlsx' ...

Excel cannot open the 'test.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.