Index: /trunk/src/org/openstreetmap/josm/gui/history/VersionInfoPanel.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/history/VersionInfoPanel.java	(revision 13534)
+++ /trunk/src/org/openstreetmap/josm/gui/history/VersionInfoPanel.java	(revision 13535)
@@ -60,4 +60,5 @@
     private final OpenChangesetDialogAction changesetDialogAction = new OpenChangesetDialogAction(null);
     private final JButton changesetButton = new JButton(changesetDialogAction);
+    private final BasicArrowButton arrowButton = new BasicArrowButton(BasicArrowButton.SOUTH);
     private JPanel pnlChangesetSource;
     private JPanel pnlChangesetImageryUsed;
@@ -114,7 +115,6 @@
         changesetButton.setMargin(new Insets(0, 0, 0, 2));
         changesetPanel.add(changesetButton, BorderLayout.CENTER);
-        final BasicArrowButton arrowButton = new BasicArrowButton(BasicArrowButton.SOUTH);
         arrowButton.addActionListener(action -> {
-            if (changesetDialogAction != null) { // fix #15444
+            if (changesetDialogAction.id != null) { // fix #15444, #16097
                 final OpenChangesetPopupMenu popupMenu = new OpenChangesetPopupMenu(changesetDialogAction.id);
                 popupMenu.insert(changesetDialogAction, 0);
@@ -258,4 +258,5 @@
             changesetDialogAction.setId(cs.getId());
             changesetButton.setEnabled(true);
+            arrowButton.setEnabled(true);
 
             String username = "";
@@ -283,4 +284,5 @@
             changesetDialogAction.setId(null);
             changesetButton.setEnabled(false);
+            arrowButton.setEnabled(false);
         }