Text encoding for your CSV file needs to be UTF-8. This is typically the default choice for most spreadsheet programs — but not always. If you're prompted to select a format when using your spreadsheet program, be sure it's UTF-8. If you receive this error, check your spreadsheet program and ensure that you're saving to the proper format.
You can also use our UTF-8 Validator for instant analysis.
Read this article if your CSV file contains special characters (such as á, é, í, ó, ú, ñ, ü) and you plan to use the Bundle feature.