System.Drawing was deprecated on .net 6 and there does not seem to be a replacement ready from Aspose for macOS and Linux.
I have attached a test project which fails completely on macOS, and partially on Linux.
On macO…....NET 6 Support missing for Aspose.Cells, Aspose.Imaging, Aspose...Aspose.PDF, Aspose.Slides.NET on macOS, Linux Aspose.Total Product...