Index: applications/editors/josm/plugins/utilsplugin2/src/org/openstreetmap/josm/plugins/utilsplugin2/actions/AlignWayNodesAction.java
===================================================================
--- applications/editors/josm/plugins/utilsplugin2/src/org/openstreetmap/josm/plugins/utilsplugin2/actions/AlignWayNodesAction.java	(revision 33297)
+++ applications/editors/josm/plugins/utilsplugin2/src/org/openstreetmap/josm/plugins/utilsplugin2/actions/AlignWayNodesAction.java	(revision 33328)
@@ -11,4 +11,5 @@
 import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import javax.swing.JOptionPane;
@@ -144,5 +145,5 @@
     private Set<Way> findCommonWays(Set<Node> nodes) {
         Set<Way> ways = null;
-        for (Node n : nodes) {
+        for (Node n : nodes.stream().filter(n -> n.getDataSet() != null).collect(Collectors.toList())) {
             List<Way> referrers = OsmPrimitive.getFilteredList(n.getReferrers(), Way.class);
             if (ways == null)