diff --git a/core/modules/block/config/schema/block.schema.yml b/core/modules/block/config/schema/block.schema.yml
index 64c9a3a..984400a 100644
--- a/core/modules/block/config/schema/block.schema.yml
+++ b/core/modules/block/config/schema/block.schema.yml
@@ -59,9 +59,6 @@ block.block.*:
               sequence:
                - type: string
                  label: 'Node type'
-        visibility__active_tab:
-          type: string
-          label: 'Visibility active tab'
     plugin:
       type: string
       label: 'Plugin'
diff --git a/core/modules/block/lib/Drupal/block/BlockFormController.php b/core/modules/block/lib/Drupal/block/BlockFormController.php
index 5965c21..a8c77d8 100644
--- a/core/modules/block/lib/Drupal/block/BlockFormController.php
+++ b/core/modules/block/lib/Drupal/block/BlockFormController.php
@@ -318,6 +318,11 @@ public function submit(array $form, array &$form_state) {
       'values' => &$form_state['values']['settings'],
       'errors' => $form_state['errors'],
     );
+
+    // visibility__active_tab is Form API state and not configuration.
+    // @todo Fix vertical_tabs.
+    unset($settings['values']['visibility']['visibility__active_tab']);
+
     // Call the plugin submit handler.
     $entity->getPlugin()->submitConfigurationForm($form, $settings);
 
diff --git a/core/modules/block/tests/modules/block_test/config/block.block.test_block.yml b/core/modules/block/tests/modules/block_test/config/block.block.test_block.yml
index 4b68aca..3cdcb81 100644
--- a/core/modules/block/tests/modules/block_test/config/block.block.test_block.yml
+++ b/core/modules/block/tests/modules/block_test/config/block.block.test_block.yml
@@ -18,4 +18,3 @@ visibility:
     roles: {  }
   node_type:
     types: {  }
-  visibility__active_tab: edit-visibility-path
diff --git a/core/modules/config_translation/config_translation.module b/core/modules/config_translation/config_translation.module
index 0fc1170..8666ab0 100644
--- a/core/modules/config_translation/config_translation.module
+++ b/core/modules/config_translation/config_translation.module
@@ -159,7 +159,7 @@ function config_translation_config_translation_type_info_alter(&$definitions) {
   // form elements in ConfigTranslationFormBase. Other translatable types will
   // appear as a one line textfield.
   $definitions['text']['form_element_class'] = '\Drupal\config_translation\FormElement\Textarea';
-  $definitions['date_format']['form_element_class'] = '\Drupal\config_translation\FormElement\DateFormat';
+  $definitions['date_format']['form_element_class'] = '\Drupal\coBlockFormControllernfig_translation\FormElement\DateFormat';
 }
 
 /**
diff --git a/core/profiles/minimal/config/block.block.stark_admin.yml b/core/profiles/minimal/config/block.block.stark_admin.yml
index 1c11ab5..db1e33c 100644
--- a/core/profiles/minimal/config/block.block.stark_admin.yml
+++ b/core/profiles/minimal/config/block.block.stark_admin.yml
@@ -18,4 +18,3 @@ visibility:
     roles: {  }
   node_type:
     types: {  }
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/minimal/config/block.block.stark_login.yml b/core/profiles/minimal/config/block.block.stark_login.yml
index a727ff5..776307a 100644
--- a/core/profiles/minimal/config/block.block.stark_login.yml
+++ b/core/profiles/minimal/config/block.block.stark_login.yml
@@ -18,4 +18,3 @@ visibility:
     roles: {  }
   node_type:
     types: {  }
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/minimal/config/block.block.stark_tools.yml b/core/profiles/minimal/config/block.block.stark_tools.yml
index 6073ede..64faebb 100644
--- a/core/profiles/minimal/config/block.block.stark_tools.yml
+++ b/core/profiles/minimal/config/block.block.stark_tools.yml
@@ -18,4 +18,3 @@ visibility:
     roles: {  }
   node_type:
     types: {  }
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_breadcrumbs.yml b/core/profiles/standard/config/block.block.bartik_breadcrumbs.yml
index c915c46..3db2104 100644
--- a/core/profiles/standard/config/block.block.bartik_breadcrumbs.yml
+++ b/core/profiles/standard/config/block.block.bartik_breadcrumbs.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_content.yml b/core/profiles/standard/config/block.block.bartik_content.yml
index 5b7187b..01fa454 100644
--- a/core/profiles/standard/config/block.block.bartik_content.yml
+++ b/core/profiles/standard/config/block.block.bartik_content.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_footer.yml b/core/profiles/standard/config/block.block.bartik_footer.yml
index 2ad2766..9a99179 100644
--- a/core/profiles/standard/config/block.block.bartik_footer.yml
+++ b/core/profiles/standard/config/block.block.bartik_footer.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_help.yml b/core/profiles/standard/config/block.block.bartik_help.yml
index c697560..b951e65 100644
--- a/core/profiles/standard/config/block.block.bartik_help.yml
+++ b/core/profiles/standard/config/block.block.bartik_help.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_login.yml b/core/profiles/standard/config/block.block.bartik_login.yml
index e94f562..7b8d60a 100644
--- a/core/profiles/standard/config/block.block.bartik_login.yml
+++ b/core/profiles/standard/config/block.block.bartik_login.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_powered.yml b/core/profiles/standard/config/block.block.bartik_powered.yml
index 265f271..cdf4572 100644
--- a/core/profiles/standard/config/block.block.bartik_powered.yml
+++ b/core/profiles/standard/config/block.block.bartik_powered.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_search.yml b/core/profiles/standard/config/block.block.bartik_search.yml
index d37e197..ecc510a 100644
--- a/core/profiles/standard/config/block.block.bartik_search.yml
+++ b/core/profiles/standard/config/block.block.bartik_search.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.bartik_tools.yml b/core/profiles/standard/config/block.block.bartik_tools.yml
index b940651..38d105d 100644
--- a/core/profiles/standard/config/block.block.bartik_tools.yml
+++ b/core/profiles/standard/config/block.block.bartik_tools.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.seven_breadcrumbs.yml b/core/profiles/standard/config/block.block.seven_breadcrumbs.yml
index d314031..ed4ee84 100644
--- a/core/profiles/standard/config/block.block.seven_breadcrumbs.yml
+++ b/core/profiles/standard/config/block.block.seven_breadcrumbs.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.seven_content.yml b/core/profiles/standard/config/block.block.seven_content.yml
index 39f26ff..99ff8fd 100644
--- a/core/profiles/standard/config/block.block.seven_content.yml
+++ b/core/profiles/standard/config/block.block.seven_content.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.seven_help.yml b/core/profiles/standard/config/block.block.seven_help.yml
index 8536232..72fdeae 100644
--- a/core/profiles/standard/config/block.block.seven_help.yml
+++ b/core/profiles/standard/config/block.block.seven_help.yml
@@ -21,4 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
diff --git a/core/profiles/standard/config/block.block.seven_login.yml b/core/profiles/standard/config/block.block.seven_login.yml
index d3e62fa..5efa88c 100644
--- a/core/profiles/standard/config/block.block.seven_login.yml
+++ b/core/profiles/standard/config/block.block.seven_login.yml
@@ -21,5 +21,3 @@ visibility:
     types:
       article: '0'
       page: '0'
-  visibility__active_tab: edit-visibility-path
-