Index: /trunk/src/org/openstreetmap/josm/tools/OverpassTurboQueryWizard.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/tools/OverpassTurboQueryWizard.java	(revision 10801)
+++ /trunk/src/org/openstreetmap/josm/tools/OverpassTurboQueryWizard.java	(revision 10802)
@@ -38,5 +38,7 @@
 
     private OverpassTurboQueryWizard() {
-
+        if (engine == null) {
+            throw new IllegalStateException("Failed to retrieve JavaScript engine");
+        }
         try (CachedFile file = new CachedFile("resource://data/overpass-wizard.js");
              Reader reader = file.getContentReader()) {