Hi. The scenario i have is as follow: we are loading multiple dxf files from external sources, add them as blocks into DxfModel and position them and rotate via insertions to output DxfModel and save it via DxfWriter or DwgWriter. In some cases, when using eihter DxfWriter or DwgWriter, we are getting excpetions: Unknown b-spline rationality type : 1 or Unknown b-spline rationality type : 2 with call stack starting in: WW.Cad.Model.Entities.DxfModelerGeometry.( , Boolean ) WW.Cad.Model.Entities.DxfModelerGeometry.( ) WW.Cad.Model.Entities.DxfModelerGeometry.get_SabStreamFromSAT() WW.Cad.Model.DxfModel.( ,  , List`1 , DxfEntity ) WW.Cad.Model.DxfModel.() WW.Cad.IO.DxfWriter.() WW.Cad.IO.DxfWriter.Write(Boolean validate) All dxf files that are used can be open ie. in AutoCad - so they dont seem to be invalid dxf files - and also DxfReader works for all of them. Almost all of data is stored as Dxf3DSolid with SatText set. Do you by chance have idea what could causing this exception?

Can you share an input file that has this data (please zip dxf file)? - Wout