While using Aspose.Cells 7.7, an exception is thrown when attempting to open the attached file, however this file can be opened in Microsoft Excel.
Thanks for your posting and using Aspose.Cells.
We were able to replicate this exception using your source file with the latest version of Aspose.Cells. When the file is opened with Aspose.Cells API, it throws exception as you mentioned. We have logged this issue in our database. We will look into it and fix this issue. Once, the issue is resolved or we have some other update for you, we will let you know asap.
This issue has been logged as CELLSNET-42253.