diff -u b/core/modules/config/src/ConfigSubscriber.php b/core/modules/config/src/ConfigSubscriber.php
--- b/core/modules/config/src/ConfigSubscriber.php
+++ b/core/modules/config/src/ConfigSubscriber.php
@@ -7,34 +7,28 @@
 
 namespace Drupal\config;
 
-use Drupal\Core\Config\BatchConfigImporter;
 use Drupal\Core\Config\ConfigEvents;
 use Drupal\Core\Config\ConfigImporterEvent;
 use Drupal\Core\Config\ConfigImporterException;
-use Drupal\Core\Config\StorageDispatcher;
-use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Drupal\Core\Config\ConfigImportValidateEventSubscriberBase;
+
 
 /**
  * Config subscriber.
  */
-class ConfigSubscriber implements EventSubscriberInterface {
+class ConfigSubscriber extends ConfigImportValidateEventSubscriberBase {
 
   /**
    * Checks that the Configuration module is not being uninstalled.
    *
    * @param ConfigImporterEvent $event
    *   The config import event.
-   *
-   * @throws \Drupal\Core\Config\ConfigImporterException
-   *   Exception thrown if the Configuration module is being uninstalled.
    */
   public function onConfigImporterValidate(ConfigImporterEvent $event) {
     $importer = $event->getConfigImporter();
-    if ($importer instanceof BatchConfigImporter) {
-      $core_extension = $importer->getStorageComparer()->getSourceStorage()->read('core.extension');
-      if (!isset($core_extension['module']['config'])) {
-        throw new ConfigImporterException(t('Can not uninstall the Configuration module as part of a configuration synchronization through the user interface.'));
-      }
+    $core_extension = $importer->getStorageComparer()->getSourceStorage()->read('core.extension');
+    if (!isset($core_extension['module']['config'])) {
+      $importer->logError($this->t('Can not uninstall the Configuration module as part of a configuration synchronization through the user interface.'));
     }
   }
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Config/ConfigImporter.php
+++ b/core/lib/Drupal/Core/Config/ConfigImporter.php
@@ -540,6 +540,7 @@ public function initialize() {
     // We have extensions to process.
     if ($this->totalExtensionsToProcess > 0) {
       $sync_steps[] = 'processExtensions';
+      $sync_steps[] = 'flush';
     }
     $sync_steps[] = 'processConfigurations';
 
@@ -550,6 +551,20 @@ public function initialize() {
   }
 
   /**
+   * Flushes Drupal's caches.
+   */
+  public function flush(array &$context) {
+    // Rebuild the container and flush Drupal's caches. If the container is not
+    // rebuilt first the entity types are not discovered correctly due to using
+    // an entity manager that has the incorrect container namespaces injected.
+    \Drupal::service('kernel')->rebuildContainer(TRUE);
+    drupal_flush_all_caches();
+    $this->reInjectMe();
+    $context['message'] = $this->t('Flushed all caches.');
+    $context['finished'] = 1;
+  }
+
+  /**
    * Processes extensions as a batch operation.
    *
    * @param array $context.
only in patch2:
unchanged:
--- a/core/modules/migrate/src/Entity/Migration.php
+++ b/core/modules/migrate/src/Entity/Migration.php
@@ -79,6 +79,13 @@ class Migration extends ConfigEntityBase implements MigrationInterface, Requirem
   public $process;
 
   /**
+   * The configuration describing the load plugins.
+   *
+   * @var array
+   */
+  public $load;
+
+  /**
    * The cached process plugins.
    *
    * @var array
@@ -339,18 +346,4 @@ public function checkRequirements() {
     return TRUE;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function toArray() {
-    // @todo Remove once migration config entities have schema
-    //   https://drupal.org/node/2183957.
-    $class_info = new \ReflectionClass($this);
-    foreach ($class_info->getProperties(\ReflectionProperty::IS_PUBLIC) as $property) {
-      $name = $property->getName();
-      $properties[$name] = $this->get($name);
-    }
-    return $properties;
-  }
-
 }
only in patch2:
unchanged:
--- a/core/modules/simpletest/src/Form/SimpletestResultsForm.php
+++ b/core/modules/simpletest/src/Form/SimpletestResultsForm.php
@@ -48,6 +48,12 @@ public static function create(ContainerInterface $container) {
    */
   public function __construct(Connection $database) {
     $this->database = $database;
+  }
+
+  /**
+   * Builds the status image map.
+   */
+  protected function buildStatusImageMap() {
     // Initialize image mapping property.
     $image_pass = array(
       '#theme' => 'image',
@@ -96,6 +102,7 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state, $test_id = NULL) {
+    $this->buildStatusImageMap();
     // Make sure there are test results to display and a re-run is not being
     // performed.
     $results = array();