Column number {0} does not have a label. To import a file by column labels, all columns must be labeled. Do you want to continue?
Explanation
When you import a spreadsheet by using the 'By column labels' option, the first row of the file must contain labels for all of the columns.
User response
To create labels for each column, click Cancel, open the file, and add labels for each column. Then, reimport the file. Click 'Confirm' to continue the import.