diff --git a/core/modules/views/src/Tests/Handler/HandlerTest.php b/core/modules/views/src/Tests/Handler/HandlerTest.php
index b182dee..15f9def 100644
--- a/core/modules/views/src/Tests/Handler/HandlerTest.php
+++ b/core/modules/views/src/Tests/Handler/HandlerTest.php
@@ -24,7 +24,7 @@ class HandlerTest extends ViewTestBase {
    *
    * @var array
    */
-  public static $testViews = array('test_view', 'test_view_handler_weight', 'test_handler_relationships', 'test_handler_test_access', 'test_filter_in_operator_ui');
+  public static $testViews = array('test_view', 'test_view_handler_weight', 'test_handler_relationships', 'test_handler_test_access', 'test_filter_in_operator_ui', 'test_exposed_relationship_admin_ui');
 
   /**
    * Modules to enable.
@@ -277,7 +277,7 @@ public function testSetRelationship() {
     // Setup a broken relationship.
     $view->addHandler('default', 'relationship', $this->randomMachineName(), $this->randomMachineName(), array(), 'broken_relationship');
     // Setup a valid relationship.
-    $view->addHandler('default', 'relationship', 'comment_field_data', 'node', array('relationship' => 'cid'), 'valid_relationship');
+    $view->addHandler('default', 'relationship', 'comment_field_data', 'node', array('relationship' => 'comment_cid'), 'valid_relationship');
     $view->initHandlers();
     $field = $view->field['title'];
 
@@ -306,6 +306,22 @@ public function testSetRelationship() {
   }
 
   /**
+   * Tests missing relationship.
+   */
+  public function testMissingRelationship() {
+    $view = Views::getView('test_exposed_relationship_admin_ui');
+    $view->build();
+    $fields = array_keys($view->field);
+    $this->assertTrue(in_array('created', $fields), 'Field without missing relationships found');
+
+    $view = Views::getView('test_exposed_relationship_admin_ui');
+    $view->removeHandler('default', 'relationship', 'uid');
+    $view->build();
+    $fields = array_keys($view->field);
+    $this->assertTrue(!in_array('created', $fields), 'Field with missing relationship not found');
+  }
+
+  /**
    * Tests the placeholder function.
    *
    * @see \Drupal\views\Plugin\views\HandlerBase::placeholder()
diff --git a/core/modules/views/src/Tests/Plugin/DisplayTest.php b/core/modules/views/src/Tests/Plugin/DisplayTest.php
index bacfdd4..9fc28b0 100644
--- a/core/modules/views/src/Tests/Plugin/DisplayTest.php
+++ b/core/modules/views/src/Tests/Plugin/DisplayTest.php
@@ -22,7 +22,7 @@ class DisplayTest extends PluginTestBase {
    *
    * @var array
    */
-  public static $testViews = array('test_filter_groups', 'test_get_attach_displays', 'test_view', 'test_display_more', 'test_display_invalid', 'test_display_empty');
+  public static $testViews = array('test_filter_groups', 'test_get_attach_displays', 'test_view', 'test_display_more', 'test_display_invalid', 'test_display_empty', 'test_exposed_relationship_admin_ui');
 
   /**
    * Modules to enable.
@@ -280,6 +280,33 @@ public function testInvalidDisplayPlugins() {
   }
 
   /**
+   * Tests display validation when a required relationship is missing.
+   */
+  public function testMissingRelationship() {
+    $errorMessage = 'You can not remove this relationship because it is used by other handlers.';
+
+    $view = Views::getView('test_exposed_relationship_admin_ui');
+
+    // Remove relationship
+    $view->removeHandler('default', 'relationship', 'uid_1');
+    $errors = $view->validate();
+    // Check no error message
+    $errorFound = !empty($errors['default']) && in_array($errorMessage, $errors['default']);
+    $this->assertTrue(!$errorFound, 'Error message not found for removed relationship');
+
+    // Unset cached relationships (see DisplayPluginBase::getHandlers())
+    unset($view->display_handler->handlers['relationship']);
+
+    // Remove requried relationship
+    $view->removeHandler('default', 'relationship', 'uid');
+    // Validate display
+    $errors = $view->validate();
+    // Check error message
+    $errorFound = !empty($errors['default']) && in_array($errorMessage, $errors['default']);
+    $this->assertTrue($errorFound, 'Error message found for required relationship');
+  }
+
+  /**
    * Tests the outputIsEmpty method on the display.
    */
   public function testOutputIsEmpty() {
diff --git a/core/modules/views/tests/modules/views_test_config/test_views/views.view.test_exposed_relationship_admin_ui.yml b/core/modules/views/tests/modules/views_test_config/test_views/views.view.test_exposed_relationship_admin_ui.yml
new file mode 100644
index 0000000..a5a910c
--- /dev/null
+++ b/core/modules/views/tests/modules/views_test_config/test_views/views.view.test_exposed_relationship_admin_ui.yml
@@ -0,0 +1,298 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - node
+id: test_exposed_relationship_admin_ui
+label: test_exposed_relationship_admin_ui
+module: views
+description: ''
+tag: ''
+base_table: node
+base_field: nid
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: 0
+    provider: views
+    display_options:
+      access:
+        type: perm
+        options:
+          perm: 'access content'
+        provider: user
+        dependencies: {  }
+      cache:
+        type: none
+        options: {  }
+        provider: views
+        dependencies: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: false
+          query_tags: {  }
+        provider: views
+        dependencies: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+        provider: views
+        dependencies: {  }
+      pager:
+        type: full
+        options:
+          items_per_page: 10
+          offset: 0
+          id: 0
+          total_pages: null
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+          tags:
+            previous: '‹ previous'
+            next: 'next ›'
+            first: '« first'
+            last: 'last »'
+          quantity: 9
+        provider: views
+        dependencies: {  }
+      style:
+        type: default
+        options:
+          grouping: {  }
+          row_class: ''
+          default_row_class: true
+          uses_fields: false
+        provider: views
+        dependencies: {  }
+      row:
+        type: fields
+        options:
+          inline: {  }
+          separator: ''
+          hide_empty: false
+          default_field_elements: true
+        provider: views
+        dependencies: {  }
+      fields:
+        title:
+          id: title
+          table: node_field_data
+          field: title
+          provider: node
+          label: ''
+          alter:
+            alter_text: false
+            make_link: false
+            absolute: false
+            trim: false
+            word_boundary: false
+            ellipsis: false
+            strip_tags: false
+            html: false
+          hide_empty: false
+          empty_zero: false
+          link_to_node: 1
+          relationship: none
+          group_type: group
+          admin_label: ''
+          dependencies: {  }
+          exclude: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_alter_empty: true
+        login:
+          id: login
+          table: users_field_data
+          field: login
+          relationship: uid
+          group_type: group
+          admin_label: ''
+          dependencies:
+            module:
+              - views
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: ''
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          date_format: html_date
+          custom_date_format: ''
+          timezone: ''
+          plugin_id: date
+          provider: views
+        created:
+          id: created
+          table: users_field_data
+          field: created
+          relationship: uid
+          group_type: group
+          admin_label: ''
+          dependencies:
+            module:
+              - views
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: ''
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: false
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          date_format: html_date
+          custom_date_format: ''
+          timezone: ''
+          plugin_id: date
+          provider: views
+      filters:
+        status:
+          value: true
+          table: node_field_data
+          field: status
+          provider: node
+          id: status
+          expose:
+            operator: ''
+          group: 1
+      sorts:
+        created:
+          id: created
+          table: node_field_data
+          field: created
+          order: DESC
+          relationship: none
+          group_type: group
+          admin_label: ''
+          dependencies: {  }
+          exposed: false
+          expose:
+            label: ''
+          granularity: second
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships:
+        uid:
+          id: uid
+          table: node_field_data
+          field: uid
+          relationship: none
+          group_type: group
+          admin_label: author
+          dependencies:
+            module:
+              - views
+          required: false
+          plugin_id: standard
+          provider: views
+        uid_1:
+          id: uid_1
+          table: node_field_data
+          field: uid
+          relationship: none
+          group_type: group
+          admin_label: 'author 2'
+          dependencies:
+            module:
+              - views
+          required: false
+          plugin_id: standard
+          provider: views
+      arguments: {  }
+      field_langcode: '***LANGUAGE_language_content***'
+      field_langcode_add_to_query: null
diff --git a/core/modules/views_ui/src/Tests/ExposedRelationshipFormUITest.php b/core/modules/views_ui/src/Tests/ExposedRelationshipFormUITest.php
new file mode 100644
index 0000000..5f61ee7
--- /dev/null
+++ b/core/modules/views_ui/src/Tests/ExposedRelationshipFormUITest.php
@@ -0,0 +1,52 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\views_ui\Tests\ExposedRelationshipFormUITest.
+ */
+
+
+namespace Drupal\views_ui\Tests;
+
+/**
+ * Tests required relationship exposed form validation.
+ *
+ * @group views_ui
+ */
+class ExposedRelationshipFormUITest extends UITestBase {
+
+  /**
+   * Views used by this test.
+   *
+   * @var array
+   */
+  public static $testViews = array('test_exposed_relationship_admin_ui');
+
+  /**
+   * Tests the admin interface of relationships.
+   */
+  function testRequiredRelataionshipRemovalAdminUI() {
+    // \Drupal::moduleHandler()->install(array('views_test_config'));
+
+    $edit = array();
+    $validationMessage = t('You can not remove this relationship because it is used by other handlers.');
+
+    $this->drupalGet('admin/structure/views/nojs/handler/test_exposed_relationship_admin_ui/default/relationship/uid');
+
+    // Click the Remove button.
+    $this->drupalPostForm('admin/structure/views/nojs/handler/test_exposed_relationship_admin_ui/default/relationship/uid', $edit, t('Remove'));
+
+    // Validation error message found for requried relationship.
+    $this->assertText($validationMessage, 'Validation error found.');
+
+
+
+     $this->drupalGet('admin/structure/views/nojs/handler/test_exposed_relationship_admin_ui/default/relationship/uid_1');
+
+    // Click the Remove button.
+    $this->drupalPostForm('admin/structure/views/nojs/handler/test_exposed_relationship_admin_ui/default/relationship/uid_1', $edit, t('Remove'));
+
+    // Validation error message not found for non-requried relationship.
+    $this->assertNoText($validationMessage, 'Validation error not found.');
+  }
+}