PDF to PPTX converts in Winforms but not in ASP.NET

When I convert PDF to PPTX using Aspose.PDF in Windows Forms, it gets converted perfectly.
But when I convert PDF to PPTX using Aspose.PDF in ASP.NET, it shows error at a code line.
Code given below:
//pdf document at location filePath_O
Aspose.Pdf.Document document = new Aspose.Pdf.Document(filePath_O);

//at this line of code it shows error
Aspose.Pdf.PptxSaveOptions pptx_save = new Aspose.Pdf.PptxSaveOptions();
//|Error|CS0234|The type or namespace name ‘PptxSaveOptions’ does not exist in the //namespace ‘Aspose.Pdf’ (are you missing an assembly reference?)

//below mentioned line also works well
document.Save(download_file);
Please help here - Aspose.Pdf.PptxSaveOptions is enabled in Winforms application but not in my ASP.NET application.

@mk10

Thank you for contacting support.

We would like to request you to ensure using Aspose.PDF for .NET 18.6 in your environment. In case the issue persists, kindly share a narrowed down sample application reproducing this issue so that we may investigate further to help you out.

I AsposePDFdllVersion.jpg (226.0 KB)
version of Aspose.PDF for .NET is:
File Version: 9.8.0.0
Product Version: 2014.11.14

Here is the narrowed down code I have written in ASP.NET:
// Load PDF document
Aspose.Pdf.Document document = new Aspose.Pdf.Document(filePath_O);
// Instantiate PptxSaveOptions instance
Aspose.Pdf.PptxSaveOptions pptx_save = new Aspose.Pdf.PptxSaveOptions();
// Save the output in PPTX format.
document.Save(download_files);

@mk10

We have worked with the code shared by you in ASP.NET application but we are unable to reproduce mentioned issue. We would like to request you to upgrade to Aspose.PDF for .NET 18.6 as it includes more features and bug fixes. Also, the support is provided based on latest available version. In case the problem persists, please create a narrowed down sample application reproducing it, so that we may proceed to help you out.