System.Exception occurred
  HResult=-2146233088
  Message=Incorrect geomentry drawing type: System.Windows.Media.CombinedGeometry
  Source=MindFusion.Diagramming.Wpf.PdfExport
  StackTrace:
       at A.GQ.U(Geometry A, Transform B)
  InnerException: 

Code (HTML)

                <diag:Diagram Name="diagram" AlignToGrid="True" ShowGrid="True"
						  AllowDrop="True" Behavior="DrawLinks" GridSizeX="20" GridSizeY="20"
						  NodesExpandable="True"
                          NodeSelected="diagram_NodeSelected"
						  NodeClicked="diagram_NodeClicked"
						  NodeDeleting="diagram_NodeDeleting"
                          LinkCreated="diagram_LinkCreated"
                          LinkModified="diagram_LinkModified"
						  LinkModifying="diagram_LinkModifying"
						  LinkCreating="diagram_LinkCreating"
						  LinkSelecting="diagram_LinkSelecting"
						  NodeCreated="diagram_NodeCreated"
                          NodeModifying="diagram_NodeModifying"
                          NodeModified="diagram_NodeModified"
						  Drop="diagram_Drop"
						  Loaded="diagram_Loaded"
                          Clicked="diagram_Clicked"
						LinkHeadShapeSize="16">
                    <diag:Diagram.ShapeNodeStyle>
                        <Style TargetType="{x:Type diag:ShapeNode}">
                            <Setter Property="FontSize" Value="11" />
                            <Setter Property="Brush">
                                <Setter.Value>
                                    <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.8,1">
                                        <GradientStop Color="#FFAFBFDF" Offset="0" />
                                        <GradientStop Color="#FFEFEFFF" Offset="0.3" />
                                        <GradientStop Color="#FF8F9FBF" Offset="0.9" />
                                        <GradientStop Color="#FF6F7FAF" Offset="1" />
                                    </LinearGradientBrush>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </diag:Diagram.ShapeNodeStyle>
                    <diag:Diagram.BackBrush>
                        <LinearGradientBrush StartPoint="0.5, 0" EndPoint="0.8, 1">
                            <GradientStop Color="#FFDFDFDF" Offset="0" />
                            <GradientStop Color="#FFEFEFFF" Offset="0.3" />
                            <GradientStop Color="#FF8F9FBF" Offset="0.9" />
                            <GradientStop Color="#FF6F7FAF" Offset="1" />
                        </LinearGradientBrush>
                    </diag:Diagram.BackBrush>
                </diag:Diagram>
 

Code (Java)

public MyDiagramView()
{
            InitializeComponent();

            diagram.AllowDrop = true;
            diagram.DocumentPlane.AllowDrop = true;

            diagram.BackBrush = this.Background;
            diagram.NodeEffects.Add(new AeroEffect());

            diagram.LinkHeadShape = ArrowHeads.RevTriangle;
            diagram.LinkHeadShapeSize = 16;
            diagram.LoadFromString("+HBvg72n0mG7RITj4R0oR/AoAUGmwMvE7PVNtvJtLnPzR2NgaiJ2uhSOmEvyxIvej3JCzCbDfAo5+T/PRK3215wAAA==");
}

private void ExportPdfButton_Click(object sender, RoutedEventArgs e)
{
            SaveFileDialog dlg = new SaveFileDialog();
            dlg.FileName = "Diagram";
            dlg.DefaultExt = ".pdf";
            dlg.Filter = "PDF documents (.pdf)|*.pdf";

            Nullable<bool> result = dlg.ShowDialog();

            if (result == true)
            {
                // Save document
                string filename = dlg.FileName;
                PdfExporter exporter = new PdfExporter();
                exporter.Export(diagram, filename);
            }
}