For the attached file Aspose.Slides.Presentation.GetThumbnails failed with Object reference not set to an instance of an object when running on Linux with Aspose.Slides.NET 22.4.0 as a .NET Core 3.1 application.
Creating a new Presentation object from “test.pptx” file is throwing that exception before calling the GetThumbnails method on my end. I’ve added a ticket with ID SLIDESNET-43179 to our issue tracking system. We apologize for any inconvenience. Our development team will investigate this case. You will be notified when the issue is resolved.
Could you please specify the Linux version where you are experiencing this error?
Thanks for the feedback @Andrey_Potapov. Your are surely right about the exception source. I previously had issued with GetThumbnails and must not have looked correctly in this case.