diff --git a/ExportDXF/ExportDXF.csproj b/ExportDXF/ExportDXF.csproj
index cf38eb4..ee669e0 100644
--- a/ExportDXF/ExportDXF.csproj
+++ b/ExportDXF/ExportDXF.csproj
@@ -22,7 +22,7 @@
     <UpdatePeriodically>false</UpdatePeriodically>
     <UpdateRequired>false</UpdateRequired>
     <MapFileExtensions>true</MapFileExtensions>
-    <ApplicationRevision>11</ApplicationRevision>
+    <ApplicationRevision>12</ApplicationRevision>
     <ApplicationVersion>1.0.0.%2a</ApplicationVersion>
     <UseApplicationTrust>false</UseApplicationTrust>
     <PublishWizardCompleted>true</PublishWizardCompleted>
diff --git a/ExportDXF/Forms/MainForm.cs b/ExportDXF/Forms/MainForm.cs
index 77a5540..5e709ec 100644
--- a/ExportDXF/Forms/MainForm.cs
+++ b/ExportDXF/Forms/MainForm.cs
@@ -286,6 +286,12 @@ namespace ExportDXF.Forms
 				var model = item.Component.GetModelDoc2() as ModelDoc2;
 				var part = model as PartDoc;
 
+				if (part == null)
+				{
+					Print(model.GetTitle() + " - skipped, not a part document");
+					continue;
+				}
+
 				var config = item.Component.ReferencedConfiguration;
 
 				var sheetMetal = model.GetFeatureByTypeName("SheetMetal");