In a C# environment using these packages
<PackageReference Include="Aspose.Cells" Version="24.10.0" />
<PackageReference Include="Aspose.Slides.NET" Version="24.10.0" />
I have this powerpoint file with 1 slide
slide …...image, please try replacing the line ole.SubstitutePictureFor.Picture...updating to 25.12 and changing this line fixes both issues outlined here...