Index: trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/AbstractMapRenderer.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/AbstractMapRenderer.java	(revision 11991)
+++ trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/AbstractMapRenderer.java	(revision 11992)
@@ -223,9 +223,10 @@
     public void visitVirtual(Path2D path, Way w) {
         Iterator<Node> it = w.getNodes().iterator();
-        if (it.hasNext()) {
-            MapViewPoint lastP = mapState.getPointFor(it.next());
-            while (it.hasNext()) {
-                MapViewPoint p = mapState.getPointFor(it.next());
-                if (isSegmentVisible(lastP, p) && isLargeSegment(lastP, p, virtualNodeSpace)) {
+        MapViewPoint lastP = null;
+        while (it.hasNext()) {
+            Node n = it.next();
+            if (n.isLatLonKnown()) {
+                MapViewPoint p = mapState.getPointFor(n);
+                if (lastP != null && isSegmentVisible(lastP, p) && isLargeSegment(lastP, p, virtualNodeSpace)) {
                     double x = (p.getInViewX()+lastP.getInViewX())/2;
                     double y = (p.getInViewY()+lastP.getInViewY())/2;
Index: trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/OffsetIterator.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/OffsetIterator.java	(revision 11991)
+++ trunk/src/org/openstreetmap/josm/data/osm/visitor/paint/OffsetIterator.java	(revision 11992)
@@ -5,4 +5,5 @@
 import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.stream.Collectors;
 
 import org.openstreetmap.josm.data.osm.Node;
@@ -42,5 +43,5 @@
     public OffsetIterator(MapViewState mapState, List<Node> nodes, double offset) {
         this.mapState = mapState;
-        this.nodes = nodes;
+        this.nodes = nodes.stream().filter(Node::isLatLonKnown).collect(Collectors.toList());
         this.offset = offset;
         idx = 0;