Suppressing the warning lets Excel open the file without checking for format mismatches. This is useful if you trust the file and want to avoid repeated alerts.

Some Mac users have noticed that Microsoft Office files and documents, whether that’s Word docs, Excel spreadsheets, Powerpoint presentations, or otherwise, are not opening in the intended apps, or ...

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.

How to Open an XLS File in Excel. XLS files are Excel workbook files created in Excel 97 or Excel 2003. The 2007, 2010 and 2013 versions of the program use the XLSX format by default to save ...

The ‘Excel Cannot Open the File’ error usually occurs when attempting to open an older Excel file with a newer version of the software. This problem frequently arises if the file has been renamed with ...

You’ll see that the table in this step contains a column called Extension which contains the file extension for each file. If you filter this table – which will insert a new step at this point in the ...

While it is technically possible to open an Excel file in Notepad, this is not a good idea. Excel files are binary files that contain complex formatting and data structures. When you open an Excel ...

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.