diff -r c83b0ff17ac9 openide.explorer/src/org/openide/explorer/view/OutlineViewDropSupport.java
--- a/openide.explorer/src/org/openide/explorer/view/OutlineViewDropSupport.java	Fri Jan 24 10:50:59 2014 +0100
+++ b/openide.explorer/src/org/openide/explorer/view/OutlineViewDropSupport.java	Fri Jan 31 16:38:21 2014 +0100
@@ -147,7 +147,11 @@
 
     private void checkStoredGlassPane() {
         // remember current glass pane to set back at end of dragging over this compoment
-        if (!DropGlassPane.isOriginalPaneStored()) {
+        if (!DropGlassPane.isOriginalPaneStored() || dropPane == null) {
+            if (DropGlassPane.isOriginalPaneStored()) {
+                // Original panel is stored, but dropPane == null, see #236349.
+                DropGlassPane.putBackOriginal();
+            }
             Component comp = table.getRootPane().getGlassPane();
             DropGlassPane.setOriginalPane(table, comp, comp.isVisible());