Index: trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 14095)
+++ trunk/src/org/openstreetmap/josm/gui/dialogs/properties/PropertiesDialog.java	(revision 14097)
@@ -809,5 +809,6 @@
                 boolean isSelected, boolean hasFocus, int row, int column) {
             Component c = super.getTableCellRendererComponent(table, value, isSelected, false, row, column);
-            boolean isDisabledAndHidden = ((IRelation<?>) table.getValueAt(row, 0)).isDisabledAndHidden();
+            IRelation<?> relation = (IRelation<?>) table.getValueAt(row, 0);
+            boolean isDisabledAndHidden = relation != null && relation.isDisabledAndHidden();
             if (c instanceof JLabel) {
                 JLabel label = (JLabel) c;