Excel file format or extension is invalid

Solution to invalid Excel file format or extension:

1. We need to look at the suffix of the file first, open "My Computer" and find it in the upper right corner Click "Organize" and find the folder and search options

2. Select the second item "View" in the dialog box and find "Hide Known" in the advanced options. "File type extension" and uncheck the previous check

#3. Now we can see the suffix of the file. Right-click the file and "Rename" to change the file suffix. into "xls"

Recommended tutorial: excel tutorial

The above is the detailed content of Excel file format or extension is invalid. For more information, please follow other related articles on the PHP Chinese website!