do not try to display a tab that was not built

libraries/common.inc.php

@@ -101,6 +101,16 @@ require_once './libraries/Theme_Manager.class.php';
  */
 require_once './libraries/Config.class.php';
 
+/**
+ * the relation lib, tracker needs it
+ */
+require_once './libraries/relation.lib.php';
+
+/**
+ * the PMA_Tracker class
+ */
+require_once './libraries/Tracker.class.php';
+
 /**
  * the PMA_Table class
  */
@@ -982,4 +992,4 @@ if (!empty($__redirect) && in_array($__redirect, $goto_whitelist)) {
     require $__redirect;
     exit();
 }
-?>
+?>