diff -u b/core/modules/block/block.module b/core/modules/block/block.module
--- b/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -357,8 +357,26 @@
   $instances = array();
   $theme = $theme ? $theme : variable_get('theme_default', 'stark');
   $block_configs = config_get_storage_names_with_prefix('plugin.core.block.' . $theme);
+  $regions = system_region_list($theme);
   foreach ($block_configs as $config) {
     $blocks[$config] = block_load($config);
+    $config = config($config);
+    $region = $config->get('region');
+    $status = $config->get('status');
+    // Disable blocks in invalid regions.
+    if (!empty($region) && $region != BLOCK_REGION_NONE && !isset($regions[$region]) && $status == 1) {
+      drupal_set_message(t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => $config->get('id'), '%region' => $region)), 'warning');
+      // Disabled modules are moved into the BLOCK_REGION_NONE later so no
+      // need to move the block to another region.
+      $config->set('status', 0);
+      $config->save();
+    }
+    // Set region to none if not enabled and make sure status is set.
+    if (empty($status)) {
+      $config->set('region', BLOCK_REGION_NONE);
+      $config->set('status', 0);
+      $config->save();
+    }
   }
   return $blocks;
 }
diff -u b/core/modules/block/lib/Drupal/block/Tests/BlockCacheTest.php b/core/modules/block/lib/Drupal/block/Tests/BlockCacheTest.php
--- b/core/modules/block/lib/Drupal/block/Tests/BlockCacheTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockCacheTest.php
@@ -19,7 +19,7 @@
    *
    * @var array
    */
-  public static $modules = array('block', 'block_test');
+  public static $modules = array('block', 'block_test', 'views');
 
   protected $admin_user;
   protected $normal_user;
only in patch2:
unchanged:
--- a/core/modules/block/lib/Drupal/block/Tests/BlockInvalidRegionTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockInvalidRegionTest.php
@@ -32,7 +32,11 @@ public static function getInfo() {
   function setUp() {
     parent::setUp();
     // Create an admin user.
-    $admin_user = $this->drupalCreateUser(array('administer site configuration', 'access administration pages'));
+    $admin_user = $this->drupalCreateUser(array(
+      'administer site configuration',
+      'access administration pages',
+      'administer blocks',
+    ));
     $this->drupalLogin($admin_user);
   }
 
@@ -41,20 +45,21 @@ function setUp() {
    */
   function testBlockInInvalidRegion() {
     // Enable a test block in the default theme and place it in an invalid region.
-    db_merge('block')
-      ->key(array(
-        'module' => 'block_test',
-        'delta' => 'test_html_id',
-        'theme' => variable_get('theme_default', 'stark'),
-      ))
-      ->fields(array(
-        'status' => 1,
-        'region' => 'invalid_region',
-        'cache' => DRUPAL_NO_CACHE,
-      ))
-      ->execute();
+    $current_theme = variable_get('default_theme', 'stark');
+    $machine_name = 'test_html_id';
+    $block = array(
+      'machine_name' => $machine_name,
+      'region' => 'footer',
+    );
+    $this->drupalPost("admin/structure/block/manage/test_html_id/$current_theme", $block, t('Save block'));
+    $this->assertText(t('The block configuration has been saved.'), 'Block was saved.');
+
+    $machine_name = 'plugin.core.block.' . $current_theme . '.' . $machine_name;
+    $config = config($machine_name);
+    $config->set('region', 'invalid_region');
+    $config->save();
 
-    $warning_message = t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => t('Test block html id'), '%region' => 'invalid_region'));
+    $warning_message = t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => $config->get('id'), '%region' => 'invalid_region'));
 
     // Clearing the cache should disable the test block placed in the invalid region.
     $this->drupalPost('admin/config/development/performance', array(), 'Clear all caches');
@@ -65,17 +70,9 @@ function testBlockInInvalidRegion() {
     $this->assertNoRaw($warning_message, 'Disabled block in the invalid region will not trigger the warning.');
 
     // Place disabled test block in the invalid region of the default theme.
-    db_merge('block')
-      ->key(array(
-        'module' => 'block_test',
-        'delta' => 'test_html_id',
-        'theme' => variable_get('theme_default', 'stark'),
-      ))
-      ->fields(array(
-        'region' => 'invalid_region',
-        'cache' => DRUPAL_NO_CACHE,
-      ))
-      ->execute();
+    $config = config($machine_name);
+    $config->set('region', 'invalid_region');
+    $config->save();
 
     // Clear the cache to check if the warning message is not triggered.
     $this->drupalPost('admin/config/development/performance', array(), 'Clear all caches');