Index: applications/editors/josm/plugins/livegps/livegps/LiveGpsPlugin.java
===================================================================
--- applications/editors/josm/plugins/livegps/livegps/LiveGpsPlugin.java	(revision 3892)
+++ applications/editors/josm/plugins/livegps/livegps/LiveGpsPlugin.java	(revision 3895)
@@ -151,8 +151,10 @@
     @Override
     public void mapFrameInitialized(MapFrame oldFrame, MapFrame newFrame) {
-        // add dialog
-        newFrame.addToggleDialog(lgpsdialog = new LiveGpsDialog(newFrame));
-        // connect listeners with acquirer:
-        addPropertyChangeListener(lgpsdialog);
+        if(newFrame != null) {
+            // add dialog
+            newFrame.addToggleDialog(lgpsdialog = new LiveGpsDialog(newFrame));
+            // connect listeners with acquirer:
+            addPropertyChangeListener(lgpsdialog);
+        }
     }
 
@@ -166,2 +168,3 @@
 
 }
+