https://github.com/Portree-Kid/flightgear-airports/issues/28

src/renderer/loaders/ParkingSpot.js

@@ -171,13 +171,14 @@ L.ParkingSpot = L.Circle.extend({
             var leftIntermediate = turf.destination(leftFront, halfRadiusKM, backwards, options);
             var rightIntermediate = turf.destination(rightFront, halfRadiusKM, backwards, options);
 
-            if(this.box === undefined ) {
+            if(this.box === undefined && this.editor !== undefined) {
                 var latlngs = [leftBack, rightBack, rightMiddle, rightIntermediate, rightFront, leftFront, leftIntermediate, leftMiddle].map(l => this.turfToLatLng(l));
                 this.box = L.polygon(latlngs);
                 this.box.addTo(this.editor.editLayer);    
                 this.box.on('click', function (event) {
                     console.debug("Click Parking : " + event.target);
                     if (Number(store.default.state.Editable.index) >= 0 &&
+                    this.featureLookup !== undefined &&
                     this.featureLookup[store.default.state.Editable.index]!==undefined) {
                         this.featureLookup[store.default.state.Editable.index].forEach(element => {
                             if(element.deselect !== undefined) {