If you cannot open an Excel file and see Excel cannot open the file because the file format or extension is not valid error, see this post.

If you receive Microsoft Excel cannot access the file, There are several possible reasons error message you can use the following suggestions to resolve the issue.

Didn't save your Excel workbook on a Mac? Here are four methods for recovering lost or unsaved Excel files on your Mac.

Resolve the "Cannot Be Opened Because the Developer Cannot Be Verified" issue on Mac effortlessly with expert tips and tricks. Get your system running smoothly again.

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 ...

Numbers has the ability to open Excel files so you can work on them. You can also export spreadsheets in Numbers so that they are compatible with Excel.

Sending Excel files containing crucial financial and business data has risks. To add a layer of protection, you should learn to password protect an Excel file.

The Microsoft Office Open XML File Format Converter is a stand-along tool that lets users of older versions of MS Office open and edit documents created in Office 2008 for Mac or Windows 2007 Office.