Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 4442)
+++ /CKEditor/trunk/CHANGES.html	(revision 4443)
@@ -48,4 +48,5 @@
 		<li><a href="http://dev.fckeditor.net/ticket/3918">#3918</a> : Fixed fake object is editable with Image dialog.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/4053">#4053</a> : Fixed 'Form Properties' missing from context menu when selection collapsed inside form.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/4401">#4401</a> : Fixed customized by removing 'upload' tab page from 'Link dialog' cause JavaScript error.</li>
 	</ul>
 	<h3>
Index: /CKEditor/trunk/_source/plugins/link/dialogs/link.js
===================================================================
--- /CKEditor/trunk/_source/plugins/link/dialogs/link.js	(revision 4442)
+++ /CKEditor/trunk/_source/plugins/link/dialogs/link.js	(revision 4443)
@@ -38,5 +38,6 @@
 			partIds = [ 'urlOptions', 'anchorOptions', 'emailOptions' ],
 			typeValue = this.getValue(),
-			uploadInitiallyHidden = dialog.definition.getContents( 'upload' ).hidden;
+			uploadTab = dialog.definition.getContents( 'upload' ),
+			uploadInitiallyHidden = uploadTab && uploadTab.hidden;
 
 		if ( typeValue == 'url' )