Index: trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 5756)
+++ trunk/src/org/openstreetmap/josm/gui/layer/OsmDataLayer.java	(revision 5758)
@@ -407,5 +407,7 @@
         }
         // repaint to make sure new data is displayed properly.
-        Main.map.mapView.repaint();
+        if (Main.map != null && Main.map.mapView != null) {
+            Main.map.mapView.repaint();
+        }
         warnNumNewConflicts(numNewConflicts);
     }