Index: /trunk/src/org/openstreetmap/josm/gui/datatransfer/OsmTransferHandler.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/datatransfer/OsmTransferHandler.java	(revision 10889)
+++ /trunk/src/org/openstreetmap/josm/gui/datatransfer/OsmTransferHandler.java	(revision 10890)
@@ -96,4 +96,7 @@
         } catch (IllegalStateException e) {
             Main.debug(e);
+        } catch (NullPointerException e) {
+            // JDK-6322854: On Linux/X11, NPE can happen for unknown reasons, on all versions of Java
+            Main.error(e);
         }
         return false;