Index: trunk/src/org/openstreetmap/josm/actions/AutoScaleAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/AutoScaleAction.java	(revision 12234)
+++ trunk/src/org/openstreetmap/josm/actions/AutoScaleAction.java	(revision 12235)
@@ -224,8 +224,12 @@
             return null;
         }
-        List<Layer> layers = LayerListDialog.getInstance().getModel().getSelectedLayers();
-        if (layers.isEmpty())
-            return null;
-        return layers.get(0);
+        try {
+            List<Layer> layers = LayerListDialog.getInstance().getModel().getSelectedLayers();
+            if (!layers.isEmpty())
+                return layers.get(0);
+        } catch (IllegalStateException e) {
+            Main.error(e);
+        }
+        return null;
     }