Ticket #7639: 7639_2.patch

_source/plugins/selection/plugin.js

@@ -477 +477 @@
                                 });
 
                         editor.selectionChange = checkSelectionChangeTimeout;
-                }
+                        editor.on( 'destroy', function()
+                        {
+                                // IE9 might cease to work if there's an object selection inside the iframe (#7639).
+                                if ( CKEDITOR.env.ie9Compat )
+                                {
+                                        var sel = editor.getSelection();
+                                        sel && sel.getNative().clear();
+                                }
+                        }, null, null, 10 );
+                }
         });
 
         /**