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 Excel is not opening on double-click or not responding on your Windows 11/10 PC, take a look at the addons first, or else follow these suggestions to resolve the issue.

However, if I load the Excel first, all Excel files could be accessed or displayed without any trouble. The problem makes it very inconvenient to search for a file and load it immediately.

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.