diff --git a/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php b/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
index 5f3b776..050a1ea 100644
--- a/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/Views/DisplayBlockTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\block\Tests\Views;
 
-use Drupal\block\Plugin\Core\Entity\Block;
 use Drupal\views\Tests\ViewTestBase;
 use Drupal\views\Tests\ViewTestData;
 
@@ -48,43 +47,6 @@ protected function setUp() {
   }
 
   /**
-   * Checks to see whether a block appears on the page.
-   *
-   * @param \Drupal\block\Plugin\Core\Entity\Block $block
-   *   The block entity to find on the page.
-   */
-  protected function assertBlockAppears(Block $block) {
-    $result = $this->findBlockInstance($block);
-    $this->assertTrue(!empty($result), format_string('Ensure the block @id appears on the page', array('@id' => $block->id())));
-  }
-
-  /**
-   * Checks to see whether a block does not appears on the page.
-   *
-   * @param \Drupal\block\Plugin\Core\Entity\Block $block
-   *   The block entity to find on the page.
-   */
-  protected function assertNoBlockAppears(Block $block) {
-    $result = $this->findBlockInstance($block);
-    $this->assertFalse(!empty($result), format_string('Ensure the block @id does not appear on the page', array('@id' => $block->id())));
-  }
-
-  /**
-   * Find a block instance on the page.
-   *
-   * @param \Drupal\block\Plugin\Core\Entity\Block $block
-   *   The block entity to find on the page.
-   *
-   * @return array
-   *   The result from the xpath query.
-   */
-  protected function findBlockInstance(Block $block) {
-    $config_id = explode('.', $block->id());
-    $machine_name = array_pop($config_id);
-    return $this->xpath('//div[@id = :id]', array(':id' => 'block-' . $machine_name));
-  }
-
-  /**
    * Tests removing a block display.
    */
   protected function testDeleteBlockDisplay() {
diff --git a/core/modules/views/lib/Drupal/views/DisplayBag.php b/core/modules/views/lib/Drupal/views/DisplayBag.php
index 6e7a75b..fccdf72 100644
--- a/core/modules/views/lib/Drupal/views/DisplayBag.php
+++ b/core/modules/views/lib/Drupal/views/DisplayBag.php
@@ -60,7 +60,7 @@ public function __destruct() {
    * Overrides \Drupal\Component\Plugin\PluginBag::clear().
    */
   public function clear() {
-    foreach ($this->pluginInstances as $display_id => $display) {
+    foreach (array_filter($this->pluginInstances) as $display_id => $display) {
       $display->destroy();
     }
 
@@ -88,10 +88,10 @@ protected function initializePlugin($display_id) {
       $message = $e->getMessage();
       drupal_set_message(t('!message', array('!message' => $message)), 'warning');
     }
+
+    // If no plugin instance has been created, return NULL.
     if (empty($this->pluginInstances[$display_id])) {
-      // Provide a 'default' handler as an emergency. This won't work well but
-      // it will keep things from crashing.
-      $this->pluginInstances[$display_id] = $this->manager->createInstance('default');
+      return NULL;
     }
 
     $this->pluginInstances[$display_id]->initDisplay($this->view, $display);
diff --git a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
index 8a77f18..af7cfa7 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/block/block/ViewsBlock.php
@@ -48,7 +48,6 @@ public function __construct(array $configuration, $plugin_id, array $plugin_defi
     list($name, $this->displayID) = explode('-', $delta, 2);
     // Load the view.
     $this->view = views_get_view($name);
-    $this->view->setDisplay($this->displayID);
   }
 
   /**
@@ -74,15 +73,19 @@ public function form($form, &$form_state) {
    * Implements \Drupal\block\BlockBase::build().
    */
   public function build() {
-    $output = $this->view->executeDisplay($this->displayID);
-    // Set the label to the title configured in the view.
-    $this->entity->set('label', filter_xss_admin($this->view->getTitle()));
-    // Before returning the block output, convert it to a renderable array
-    // with contextual links.
-    $this->addContextualLinks($output);
-
-    $this->view->destroy();
-    return $output;
+    if ($output = $this->view->executeDisplay($this->displayID)) {
+      // Set the label to the title configured in the view.
+      $this->entity->set('label', filter_xss_admin($this->view->getTitle()));
+      // Before returning the block output, convert it to a renderable array
+      // with contextual links.
+      $this->addContextualLinks($output);
+
+      $this->view->destroy();
+
+      return $output;
+    }
+
+    return array();
   }
 
   /**
diff --git a/core/modules/views/lib/Drupal/views/Tests/Plugin/DisplayTest.php b/core/modules/views/lib/Drupal/views/Tests/Plugin/DisplayTest.php
index 8d6e2eb..77a1c4f 100644
--- a/core/modules/views/lib/Drupal/views/Tests/Plugin/DisplayTest.php
+++ b/core/modules/views/lib/Drupal/views/Tests/Plugin/DisplayTest.php
@@ -26,7 +26,7 @@ class DisplayTest extends PluginTestBase {
    *
    * @var array
    */
-  public static $modules = array('views_ui', 'node');
+  public static $modules = array('views_ui', 'node', 'block');
 
   public static function getInfo() {
     return array(
@@ -144,9 +144,9 @@ public function testGetAttachedDisplays() {
   }
 
   /**
-   * Tests an invalid display plugin.
+   * Tests invalid display plugins.
    */
-  public function testInvalidDisplayPlugin() {
+  public function testInvalidDisplayPlugins() {
     $this->drupalGet('test_display_invalid');
     $this->assertResponse(200);
 
@@ -165,6 +165,30 @@ public function testInvalidDisplayPlugin() {
 
     $this->drupalGet('test_display_invalid');
     $this->assertResponse(404);
+
+    // Change the display plugin ID back to the correct ID.
+    $config = config('views.view.test_display_invalid');
+    $config->set('display.page_1.display_plugin', 'page');
+    $config->save();
+
+    // Place the block display.
+    $block = $this->drupalPlaceBlock('views_block:test_display_invalid-block_1', array(), array('title' => 'Invalid display'));
+
+    $this->drupalGet('<front>');
+    $this->assertResponse(200);
+    $this->assertBlockAppears($block);
+
+    // Change the block plugin ID to an invalid one.
+    $config = config('views.view.test_display_invalid');
+    $config->set('display.block_1.display_plugin', 'invalid');
+    $config->save();
+
+    // Test the page is still displayed, the block not present, and has the
+    // plugin warning message.
+    $this->drupalGet('<front>');
+    $this->assertResponse(200);
+    $this->assertText(t('The plugin (invalid) did not specify an instance class.'));
+    $this->assertNoBlockAppears($block);
   }
 
 }
diff --git a/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php b/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
index 93685aa..0836300 100644
--- a/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
+++ b/core/modules/views/lib/Drupal/views/Tests/ViewTestBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\views\Tests;
 
 use Drupal\simpletest\WebTestBase;
+use Drupal\block\Plugin\Core\Entity\Block;
 
 /**
  * Defines a base class for Views testing in the full web test environment.
@@ -224,6 +225,43 @@ protected function executeView($view, $args = array()) {
   }
 
   /**
+   * Checks to see whether a block appears on the page.
+   *
+   * @param \Drupal\block\Plugin\Core\Entity\Block $block
+   *   The block entity to find on the page.
+   */
+  protected function assertBlockAppears(Block $block) {
+    $result = $this->findBlockInstance($block);
+    $this->assertTrue(!empty($result), format_string('Ensure the block @id appears on the page', array('@id' => $block->id())));
+  }
+
+  /**
+   * Checks to see whether a block does not appears on the page.
+   *
+   * @param \Drupal\block\Plugin\Core\Entity\Block $block
+   *   The block entity to find on the page.
+   */
+  protected function assertNoBlockAppears(Block $block) {
+    $result = $this->findBlockInstance($block);
+    $this->assertFalse(!empty($result), format_string('Ensure the block @id does not appear on the page', array('@id' => $block->id())));
+  }
+
+  /**
+   * Find a block instance on the page.
+   *
+   * @param \Drupal\block\Plugin\Core\Entity\Block $block
+   *   The block entity to find on the page.
+   *
+   * @return array
+   *   The result from the xpath query.
+   */
+  protected function findBlockInstance(Block $block) {
+    $config_id = explode('.', $block->id());
+    $machine_name = array_pop($config_id);
+    return $this->xpath('//div[@id = :id]', array(':id' => 'block-' . $machine_name));
+  }
+
+  /**
    * Returns the schema definition.
    */
   protected function schemaDefinition() {
diff --git a/core/modules/views/lib/Drupal/views/ViewExecutable.php b/core/modules/views/lib/Drupal/views/ViewExecutable.php
index 9a4ba48..11ae3ce 100644
--- a/core/modules/views/lib/Drupal/views/ViewExecutable.php
+++ b/core/modules/views/lib/Drupal/views/ViewExecutable.php
@@ -688,10 +688,13 @@ public function setDisplay($display_id = NULL) {
       $this->rowPlugin = NULL;
     }
 
-    // Set a shortcut.
-    $this->display_handler = $this->displayHandlers->get($display_id);
+    if ($display = $this->displayHandlers->get($display_id)) {
+      // Set a shortcut.
+      $this->display_handler = $display;
+      return TRUE;
+    }
 
-    return TRUE;
+    return FALSE;
   }
 
   /**
@@ -1495,7 +1498,7 @@ public function access($displays = NULL, $account = NULL) {
     $displays = (array)$displays;
     foreach ($displays as $display_id) {
       if ($this->displayHandlers->has($display_id)) {
-        if ($this->displayHandlers->get($display_id)->access($account)) {
+        if (($display = $this->displayHandlers->get($display_id)) && $display->access($account)) {
           return TRUE;
         }
       }
diff --git a/core/modules/views/tests/views_test_config/test_views/views.view.test_display_invalid.yml b/core/modules/views/tests/views_test_config/test_views/views.view.test_display_invalid.yml
index 39a4c6d..7d13ccf 100644
--- a/core/modules/views/tests/views_test_config/test_views/views.view.test_display_invalid.yml
+++ b/core/modules/views/tests/views_test_config/test_views/views.view.test_display_invalid.yml
@@ -25,6 +25,11 @@ display:
     display_title: Page
     id: page_1
     position: '0'
+  block_1:
+    display_plugin: block
+    id: block_1
+    display_title: Block
+    position: '1'
 human_name: ''
 id: test_display_invalid
 tag: ''
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index 3bc0bd1..7ee7e72 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -445,10 +445,15 @@ function views_page($name, $display_id) {
 
   // Load the view and render it.
   if ($view = views_get_view($name)) {
-    return $view->executeDisplay($display_id, $args);
+    if ($output = $view->executeDisplay($display_id, $args)) {
+      return $output;
+    }
+    else {
+      return array();
+    }
   }
 
-  // Fallback; if we get here no view was found or handler was not valid.
+  // Fallback if we get here no view was found.
   return MENU_NOT_FOUND;
 }
 
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index a0f1016..7fcda31 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -444,14 +444,6 @@
 # $settings['allow_authorize_operations'] = FALSE;
 
 /**
- * Mixed-mode sessions:
- *
- * Set to TRUE to create both secure and insecure sessions when using HTTPS.
- * Defaults to FALSE.
- */
-# $settings['mixed_mode_sessions'] = TRUE;
-
-/**
  * Base URL (optional).
  *
  * If Drupal is generating incorrect URLs on your site, which could