diff --git a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/GreenEnricher.java b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/GreenEnricher.java
index 1356a5cb23be4e838c91c5220056f5f515091668..752c8f9ca345ca753991bc8bca14c8e36eaf3e43 100644
--- a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/GreenEnricher.java
+++ b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/GreenEnricher.java
@@ -218,7 +218,7 @@ public class GreenEnricher
 			WaterBody wb = new WaterBody();
 			org.xmlobjects.gml.model.geometry.primitives.Polygon poly = convertToCityGmlPoly(waterArea.getArea());
 			if (poly == null) {
-				System.out.println("Skipping WaterBody " + waterArea.getArea());
+//				System.out.println("Skipping WaterBody " + waterArea.getArea());
 				continue;
 			}
 			MultiSurface ms = new MultiSurface();
@@ -233,7 +233,7 @@ public class GreenEnricher
 		for (GreenArea ga : greenAreas) {
 			org.xmlobjects.gml.model.geometry.primitives.Polygon poly = convertToCityGmlPoly(ga.getArea());
 			if (poly == null) {
-				System.out.println("Skipping " + ga.getArea());
+//				System.out.println("Skipping " + ga.getArea());
 				continue;
 			}
 			PlantCover cover = new PlantCover();
@@ -349,7 +349,7 @@ public class GreenEnricher
 				GreenArea area2 = greenAreas.get(j);
 				if (area1.getArea().intersects(area2.getArea())) {
 					Geometry difference = area1.getArea().difference(area2.getArea());
-					System.out.println(difference);
+//					System.out.println(difference);
 					if (difference instanceof MultiPolygon) {
 						MultiPolygon multi = (MultiPolygon) difference;
 						Polygon poly1 = (Polygon) multi.getGeometryN(0);
@@ -840,7 +840,7 @@ public class GreenEnricher
 			Road road = new Road();
 			org.xmlobjects.gml.model.geometry.primitives.Polygon poly = convertToCityGmlPoly(roadArea.getArea());
 			if (poly == null) {
-				System.out.println("Skipping RoadArea: " + roadArea.getArea());
+//				System.out.println("Skipping RoadArea: " + roadArea.getArea());
 				continue;
 			}
 			MultiSurface ms = new MultiSurface();
@@ -857,7 +857,7 @@ public class GreenEnricher
 			LandUse landUse = new LandUse();
 			org.xmlobjects.gml.model.geometry.primitives.Polygon poly = convertToCityGmlPoly(landUseArea.getArea());
 			if (poly == null) {
-				System.out.println("Skipping RoadArea: " + landUseArea.getArea());
+//				System.out.println("Skipping RoadArea: " + landUseArea.getArea());
 				continue;
 			}
 			MultiSurface ms = new MultiSurface();
diff --git a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
index 3f1bddeadae5cb0add9e856ba3fd2e8f0b7e9696..4f53b3a5fec7052e48f78cc30e8e1dc7709a8897 100644
--- a/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
+++ b/enrich-citygml-with-greenarea/src/main/java/de/hft/stuttgart/citygml/green/osm/TreeKatasterData.java
@@ -42,13 +42,21 @@ public class TreeKatasterData
 				Tree tree = new Tree();
 
 				Point p = (Point) feature.getAttribute("the_geom");
+				if (p == null) {
+					throw new IllegalArgumentException("The shape file does not contain Point attribute with the name: \"the_geom\"");
+				}
 				tree.setPoint(p);
 
 				String type = feature.getAttribute("Bezeichnun").toString();
+				if (type == null) {
+					System.out.println("Ignoring tree, no attribute with name \"Bezeichnun\" found");
+					continue;
+				}
 				tree.setType(type);
 
 				Object treeHeightObject = feature.getAttribute("Baumhöhe");
 				if (treeHeightObject == null) {
+					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Baumhöhe\" found");
 					continue;
 				}
 				double treeHeight = Double.parseDouble(treeHeightObject.toString());
@@ -59,11 +67,13 @@ public class TreeKatasterData
 
 				Object crownWidth = feature.getAttribute("Kronenbrei");
 				if (crownWidth == null) {
+					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Kronenbrei\" found");
 					continue;
 				}
 				tree.setCrownRadius(Float.parseFloat(crownWidth.toString()) / 2);
 				Object trunkCirc = feature.getAttribute("Stammumfan");
 				if (trunkCirc == null) {
+					System.out.println("Ignoring tree of type " + type + ", no attribute with name \"Stammumfan\" found");
 					continue;
 				}
 				double circInCm = Double.parseDouble(trunkCirc.toString());