Update App.js

public/App.js

@@ -81,8 +81,7 @@ var initialPosition = Cesium.Cartesian3.fromDegrees(16.368084, 48.183257, 360);
 	var landuse = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({url: 'https://w2.iaf.hft-stuttgart.de/CesiumData/3DTiles/LandUse/Meidling_Vienna/tileset.json'}));
 	
 	 
-	building.show = true;
-	outdoorbuildinginstallation.show = true;
+
 	landuse.show = false;
 		
 	
@@ -258,6 +257,9 @@ function active3DTilePicker() {
             }
             // Pick a new feature
             var picked3DtileFeature = viewer.scene.pick(movement.endPosition);
+            if (!Cesium.defined(picked3DtileFeature)) {
+                               return;
+            }
   
             // Highlight the feature if it's not already selected.
             if (picked3DtileFeature !== selected.feature) {