This is relating to latest release of Aspose.CAD for .NET 19.5 . For fix - CADNET-653.
When using with .net core to convert dxf file to pdf , conversion is very slow.
It is much faster when .using Aspose.CAD for .NET 19.2 in .net code.but to make it work i need to install additional package Microsoft.Windows.Compatibility to include system.drawing.
Please verify and confirm.