When trying to generate thumbnail of a chart using ShapeThumbnailBounds.Shape, resulting image is blank. Same thing when saving thumbnail of the whole page.
Using Aspose.Slides for .NET 19.2.0
PPT-with shapes-saveas-openxmlpresentation-pptx.zip (38.3 KB)
I have worked with the presentation file shared by you and have created an issue with ID SLIDESNET-41030 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 notified once the issue will be fixed.