diff --git a/tb_megamenu.functions.inc b/tb_megamenu.functions.inc
index a4e960b..448f76b 100644
--- a/tb_megamenu.functions.inc
+++ b/tb_megamenu.functions.inc
@@ -346,7 +346,7 @@ function tb_megamenu_sync_config($items, &$item_config, $_mlid, $section) {
     foreach ($item_config['rows_content'] as $i => $row) {
       foreach ($row as $j => $col) {
         foreach ($col['col_content'] as $k => $tb_item) {
-          if ($tb_item['type'] == 'menu_item') {
+          if (isset($tb_item['type']) && $tb_item['type'] == 'menu_item') {
             $hash[$tb_item['mlid']] = array('row' => $i, 'col' => $j);
             $existed = false;
             foreach ($items as $item) {
@@ -367,7 +367,7 @@ function tb_megamenu_sync_config($items, &$item_config, $_mlid, $section) {
             }
           }
           else {
-            if (!tb_megamenu_block_content_exists($tb_item['block_key'], $section)) {
+            if (isset($tb_item['block_key']) && !tb_megamenu_block_content_exists($tb_item['block_key'], $section)) {
               unset($item_config['rows_content'][$i][$j]['col_content'][$k]);
               if (empty($item_config['rows_content'][$i][$j]['col_content'])) {
                 unset($item_config['rows_content'][$i][$j]);
@@ -426,6 +426,9 @@ function tb_megamenu_insert_tb_item(&$item_config, $row, $col, $item) {
   );
 
   foreach ($col_content as $cell) {
+    if (is_null($cell)) {
+      continue;
+    }
     $new_col[] = $cell;
     if (!$added && isset($new_config['weight'])) {
       $new_col[] = $new_config;
diff --git a/tb_megamenu.themes.inc b/tb_megamenu.themes.inc
index 929a064..158aec2 100644
--- a/tb_megamenu.themes.inc
+++ b/tb_megamenu.themes.inc
@@ -82,97 +82,99 @@ function template_preprocess_tb_megamenu_nav(&$vars) {
 
 function template_preprocess_tb_megamenu_item(&$vars) {
   $level = $vars['level'];
-  $item = $vars['item'];
-  $mlid = $item['link']['mlid'];
-  $trail = $vars['trail'];
-  $link_attributes = array();
-  $menu_config = $vars['menu_config'];
-  $item_config = isset($menu_config[$mlid]['item_config']) ? $menu_config[$mlid]['item_config'] : array();
-  tb_megamenu_edit_item_config($item_config);
-  $vars['item_config'] = $item_config;
-  if (!empty($menu_config[$mlid]['rows_content']) &&
-    ($vars['section'] == 'backend' || !$item_config['hidesub'])
-  ) {
+  if (isset($vars['item'])) {
+    $item = $vars['item'];
+    $mlid = $item['link']['mlid'];
+    $trail = $vars['trail'];
+    $link_attributes = array();
+    $menu_config = $vars['menu_config'];
+    $item_config = isset($menu_config[$mlid]['item_config']) ? $menu_config[$mlid]['item_config'] : array();
+    tb_megamenu_edit_item_config($item_config);
+    $vars['item_config'] = $item_config;
+    if (!empty($menu_config[$mlid]['rows_content']) &&
+      ($vars['section'] == 'backend' || !$item_config['hidesub'])
+    ) {
 
-    $vars['submenu'] = theme('tb_megamenu_submenu', array(
-      'menu_name' => $vars['menu_name'],
-      'parent' => $item,
-      'level' => $level,
-      'menu_config' => $vars['menu_config'],
-      'block_config' => $vars['block_config'],
-      'trail' => $vars['trail'],
-      'section' => $vars['section'],
-    ));
-  }
-  else {
-    $vars['submenu'] = NULL;
-  }
+      $vars['submenu'] = theme('tb_megamenu_submenu', array(
+        'menu_name' => $vars['menu_name'],
+        'parent' => $item,
+        'level' => $level,
+        'menu_config' => $vars['menu_config'],
+        'block_config' => $vars['block_config'],
+        'trail' => $vars['trail'],
+        'section' => $vars['section'],
+      ));
+    }
+    else {
+      $vars['submenu'] = NULL;
+    }
 
-  $vars['classes_array'][] = 'level-' . $level;
-  $vars['classes_array'][] = 'mega';
-  if (!empty($item_config['class'])) {
-    $vars['classes_array'][] = $item_config['class'];
-  }
-  if (!empty($item_config['alignsub'])) {
-    $vars['classes_array'][] = "mega-align-" . $item_config['alignsub'];
-  }
-  if ($item_config['hidewcol']) {
-    $vars['classes_array'][] = "sub-hidden-collapse";
-  }
+    $vars['classes_array'][] = 'level-' . $level;
+    $vars['classes_array'][] = 'mega';
+    if (!empty($item_config['class'])) {
+      $vars['classes_array'][] = $item_config['class'];
+    }
+    if (!empty($item_config['alignsub'])) {
+      $vars['classes_array'][] = "mega-align-" . $item_config['alignsub'];
+    }
+    if ($item_config['hidewcol']) {
+      $vars['classes_array'][] = "sub-hidden-collapse";
+    }
 
-  if ($item_config['group'] && $vars['submenu']) {
-    $vars['classes_array'][] = "mega-group";
-    $link_attributes['class'][] = 'mega-group-title';
-  }
-  elseif ($vars['submenu'] && !$item_config['hidesub']) {
-    $link_attributes['class'][] = 'dropdown-toggle';
-    if ($level == 1) {
-      $vars['classes_array'][] = 'dropdown';
+    if ($item_config['group'] && $vars['submenu']) {
+      $vars['classes_array'][] = "mega-group";
+      $link_attributes['class'][] = 'mega-group-title';
     }
-    else {
-      $vars['classes_array'][] = 'dropdown-submenu';
+    elseif ($vars['submenu'] && !$item_config['hidesub']) {
+      $link_attributes['class'][] = 'dropdown-toggle';
+      if ($level == 1) {
+        $vars['classes_array'][] = 'dropdown';
+      }
+      else {
+        $vars['classes_array'][] = 'dropdown-submenu';
+      }
     }
-  }
 
-  $vars['item']['link']['#attributes'] = $link_attributes;
-  if (!empty($item['link']['localized_options']['attributes'])) {
-    if (!(isset($item['link']['localized_options']['attributes']['title']) &&
-      $item['link']['localized_options']['attributes']['title'])
-    ) {
-      $item['link']['localized_options']['attributes']['title'] = $item['link']['title'];
+    $vars['item']['link']['#attributes'] = $link_attributes;
+    if (!empty($item['link']['localized_options']['attributes'])) {
+      if (!(isset($item['link']['localized_options']['attributes']['title']) &&
+        $item['link']['localized_options']['attributes']['title'])
+      ) {
+        $item['link']['localized_options']['attributes']['title'] = $item['link']['title'];
+      }
+      $vars['item']['link']['#attributes'] += $item['link']['localized_options']['attributes'];
     }
-    $vars['item']['link']['#attributes'] += $item['link']['localized_options']['attributes'];
-  }
 
-  // Ensure the link options are not NULL and an array.
-  $vars['item']['link']['options'] = isset($vars['item']['link']['options']) && is_array($vars['item']['link']['options']) ? $vars['item']['link']['options'] : [];
+    // Ensure the link options are not NULL and an array.
+    $vars['item']['link']['options'] = isset($vars['item']['link']['options']) && is_array($vars['item']['link']['options']) ? $vars['item']['link']['options'] : [];
 
-  if (isset($trail[$mlid])) {
-    $vars['classes_array'][] = 'active';
-    $vars['classes_array'][] = $vars['a_classes'][] = 'active-trail';
-  }
-  // Add list item attributes.
-    if (!empty($item['link']['localized_options']['item_attributes']['class'])) {
-    $vars['classes_array'][] = check_plain($item['link']['localized_options']['item_attributes']['class']);
-  }
+    if (isset($trail[$mlid])) {
+      $vars['classes_array'][] = 'active';
+      $vars['classes_array'][] = $vars['a_classes'][] = 'active-trail';
+    }
+    // Add list item attributes.
+      if (!empty($item['link']['localized_options']['item_attributes']['class'])) {
+      $vars['classes_array'][] = check_plain($item['link']['localized_options']['item_attributes']['class']);
+    }
 
-  $vars['attributes_array']['data-id'] = $mlid;
-  $vars['attributes_array']['data-level'] = $level;
-  $vars['attributes_array']['data-type'] = 'menu_item';
-  $vars['attributes_array']['data-class'] = $item_config['class'];
-  $vars['attributes_array']['data-xicon'] = $item_config['xicon'];
-  $vars['attributes_array']['data-caption'] = $item_config['caption'];
-  $vars['attributes_array']['data-alignsub'] = $item_config['alignsub'];
-  $vars['attributes_array']['data-group'] = $item_config['group'];
-  $vars['attributes_array']['data-hidewcol'] = $item_config['hidewcol'];
-  $vars['attributes_array']['data-hidesub'] = $item_config['hidesub'];
-  if ($vars['section'] == 'backend') {
-    $vars['attributes_array']['title'] = t("Menu Item");
-  }
+    $vars['attributes_array']['data-id'] = $mlid;
+    $vars['attributes_array']['data-level'] = $level;
+    $vars['attributes_array']['data-type'] = 'menu_item';
+    $vars['attributes_array']['data-class'] = $item_config['class'];
+    $vars['attributes_array']['data-xicon'] = $item_config['xicon'];
+    $vars['attributes_array']['data-caption'] = $item_config['caption'];
+    $vars['attributes_array']['data-alignsub'] = $item_config['alignsub'];
+    $vars['attributes_array']['data-group'] = $item_config['group'];
+    $vars['attributes_array']['data-hidewcol'] = $item_config['hidewcol'];
+    $vars['attributes_array']['data-hidesub'] = $item_config['hidesub'];
+    if ($vars['section'] == 'backend') {
+      $vars['attributes_array']['title'] = t("Menu Item");
+    }
 
-  if (!empty($item['link']['localized_options']['item_attributes'])) {
-    // Add additional list item attributes besides the class (which was handled separately above).
-    $vars['attributes_array'] += array_diff_key( $item['link']['localized_options']['item_attributes'], array('class' => NULL));
+    if (!empty($item['link']['localized_options']['item_attributes'])) {
+      // Add additional list item attributes besides the class (which was handled separately above).
+      $vars['attributes_array'] += array_diff_key( $item['link']['localized_options']['item_attributes'], array('class' => NULL));
+    }
   }
 }
 
@@ -289,10 +291,13 @@ function template_preprocess_tb_megamenu_column(&$vars) {
 
 function template_preprocess_tb_megamenu_subnav(&$vars) {
   $col = $vars['col'];
-//  $items = $vars['items'];
+  // $items = $vars['items'];
   $level = $vars['level'];
   $lis = array();
   foreach ($col as $tb_item) {
+    if (is_null($tb_item)) {
+      continue;
+    }
     $item = tb_megamenu_get_menu_item($vars['menu_name'], $tb_item['mlid']);
     $lis[] = theme('tb_megamenu_item', array(
       'menu_name' => $vars['menu_name'],