Thanks for your posting and using Aspose.Total.
Aspose.Cells for .NET is a part of Aspose.Total, you can use Aspose.Cells for .NET to convert your Excel files into Pdf.
For your question relating to Aspose.Cells for .NET, please note Aspose.Cells for .NET conversion to pdf is not done asynchronously but it is done synchronously.
You can verify it by writing a simple web service, below is a code that takes an input xls/xlsx file and convert it into pdf.
string filePath = @“F:\source.xlsx”;
Workbook workbook = new Workbook(filePath);
workbook.Save(filePath + “.out.pdf”);
Also, Aspose.Slides for .NET and Aspose.Words for .NET processes the file synchronously too. I am forwarding your question to Aspose.Slides and Aspose.Words team, they will help you asap.
Thanks for your inquiry and sorry for the delayed response. I am representative of Aspose.Words team. Please note that all methods (including the Save method) in Aspose.Words library are synchronous i.e. when a method returns, the operation would have been completed. On the other hand, if the method cannot complete an operation, it simply throws an exception.
Could you please attach your input Word document, you're getting this problem with, here for testing? I will investigate the issue on my side and provide you more information.