Invalid file generated when converting PPT file to PPTX

Using
var presentation = new Presentation(inputFilePath);
presentation.Save(outputFilePath, SaveFormat.Pptx);

with attached file, an invalid file which cannot be opened in PowerPoint is generated.
AllFeature-isolated.zip (80.8 KB)

@rlaskowski.sdl,

I have worked with the presentation file shared by you and have been able to observe the issue. An issue with ID SLIDESNET-39056 has been created in our issue tracking system to further investigate and resolve the issue. This thread has been linked with the issue so that you may be automatically notified once the issue will be fixed.

We are sorry for your inconvenience,

Adnan Ahmad

The issues you have found earlier (filed as SLIDESNET-39056) have been fixed in this update. This message was posted using BugNotificationTool from Downloads module by mudassir.fayyaz