diff --git a/core/lib/Drupal/Core/Entity/Annotation/EntityType.php b/core/lib/Drupal/Core/Entity/Annotation/EntityType.php
index 7f4dea1..43530a2 100644
--- a/core/lib/Drupal/Core/Entity/Annotation/EntityType.php
+++ b/core/lib/Drupal/Core/Entity/Annotation/EntityType.php
@@ -221,7 +221,12 @@ class EntityType extends Plugin {
   public $bundle_keys;
 
   /**
-   * @todo.
+   * The base path for the entity type administration page.
+   *
+   * If the entity type has a bundle, include {bundle} in the path.
+   *
+   * For example, the node entity type specifies
+   * "admin/structure/types/manage/{bundle}" as its base path.
    *
    * @var string
    */
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldDeleteForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldDeleteForm.php
index 64c4aef..5b6fa23 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldDeleteForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldDeleteForm.php
@@ -11,7 +11,7 @@
 use Drupal\field\Plugin\Core\Entity\FieldInstance;
 
 /**
- * @todo.
+ * Provides a form for removing a field instance from a bundle.
  */
 class FieldDeleteForm extends ConfirmFormBase {
 
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldEditForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldEditForm.php
index 4f64c60..279100d 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldEditForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldEditForm.php
@@ -11,7 +11,7 @@
 use Drupal\field\Plugin\Core\Entity\FieldInstance;
 
 /**
- * @todo.
+ * Provides a form for the field instance settings form.
  */
 class FieldEditForm implements FormInterface {
 
@@ -219,7 +219,7 @@ public function submitForm(array &$form, array &$form_state) {
   }
 
   /**
-   * @todo.
+   * Redirects to the field instance deletion form.
    */
   public function delete(array &$form, array &$form_state) {
     $destination = array();
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldSettingsForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldSettingsForm.php
index 3749649..6380f39 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldSettingsForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldSettingsForm.php
@@ -11,7 +11,7 @@
 use Drupal\field\Plugin\Core\Entity\FieldInstance;
 
 /**
- * @todo.
+ * Provides a form for the field settings edit page.
  */
 class FieldSettingsForm implements FormInterface {
 
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldWidgetTypeForm.php b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldWidgetTypeForm.php
index ca944b9..c461543 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldWidgetTypeForm.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Form/FieldWidgetTypeForm.php
@@ -11,7 +11,7 @@
 use Drupal\field\Plugin\Core\Entity\FieldInstance;
 
 /**
- * @todo.
+ * Provides a form for the widget selection form.
  */
 class FieldWidgetTypeForm implements FormInterface {
 
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Routing/RouteSubscriber.php b/core/modules/field_ui/lib/Drupal/field_ui/Routing/RouteSubscriber.php
index e486072..e062eb8 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Routing/RouteSubscriber.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Routing/RouteSubscriber.php
@@ -13,7 +13,7 @@
 use Symfony\Component\Routing\Route;
 
 /**
- * @todo.
+ * Subscriber for Field UI routes.
  */
 class RouteSubscriber implements EventSubscriberInterface {
 
@@ -26,7 +26,7 @@ public static function getSubscribedEvents() {
   }
 
   /**
-   * @todo.
+   * Adds routes for the Field UI.
    */
   public function routes(RouteBuildEvent $event) {
     $collection = $event->getRouteCollection();
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
index de04d97..334ce54 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuLinkStorageController.php
@@ -81,7 +81,9 @@ protected function attachLoad(&$menu_links, $load_revision = FALSE) {
     if ($routes) {
       $route_objects = drupal_container()->get('router.route_provider')->getRoutesByNames($routes);
       foreach ($routes as $entity_id => $route) {
-        $menu_links[$entity_id]->setRouteObject($route_objects[$route]);
+        if (isset($route_objects[$route])) {
+          $menu_links[$entity_id]->setRouteObject($route_objects[$route]);
+        }
       }
     }
 
diff --git a/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php b/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
index 62e541f..c69c414 100644
--- a/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
+++ b/core/modules/options/lib/Drupal/options/Tests/OptionsFieldUITest.php
@@ -266,7 +266,7 @@ protected function createOptionsField($type) {
     );
     field_create_instance($instance);
 
-    $this->admin_path = 'admin/structure/types/manage/' . $this->type . '/fields/node/' . $this->type . '.' . $this->field_name . '/field-settings';
+    $this->admin_path = 'admin/structure/types/manage/' . $this->type . '/fields/node.' . $this->type . '.' . $this->field_name . '/field-settings';
   }
 
   /**