Thanks for considering Aspose.
Your file is created using BIFF7(Excel95 or earlier versions). Aspose.Cells does not completely support BIFF7 file format. It supports BIFF7 encryption related to a few protected files. Aspose.Cells support BIFF8 or greater file formats (Excel97 - Excel2003). So you have to convert the file into greater versions.
Follow the steps for conversion:
1. Open your file "Suppliers.xls" into MS Excel (Excel97 - Excel2003).
2. Save As..."Microsoft Excel Workbook".
I have created your file into Excel 2002 format (The file is attached with this post). You may use it now.
Aspose Nanjing Team