diff --git a/core/modules/block/block.install b/core/modules/block/block.install
index 645f357..41e1cdd 100644
--- a/core/modules/block/block.install
+++ b/core/modules/block/block.install
@@ -6,7 +6,7 @@
  */
 
 /**
- * @addtogroup updates-8.0.x-beta
+ * @addtogroup updates-8.0.0-beta
  * @{
  */
 
@@ -20,29 +20,42 @@ function block_update_8001() {
     'user' => 'user.current_user_context',
   ];
 
+  $condition_plugin_id_ui_label_map = [
+    'node_type' => \Drupal::translation()->translate('Content types'),
+    'request_path' => \Drupal::translation()->translate('Pages'),
+    'user_role' => \Drupal::translation()->translate('Roles'),
+  ];
+
   $config_factory = \Drupal::configFactory();
   $message = NULL;
+  $disabled_blocks = $problematic_visibility_plugins = [];
+  // We deal with config objects directly in order to avoid invoking Entity API
+  // hooks. They can be problematic when two modules implement a specific hook,
+  // their code is updated at the same time, yet the update functions run
+  // sequentially so the second hook implementation can not rely on the data not
+  // being altered by the first hook.
   foreach ($config_factory->listAll('block.block.') as $block_config_name) {
-    // We deal with config objects directly to avoid the config entity API.
     $block = $config_factory->getEditable($block_config_name);
-    $disable_block = FALSE;
     if ($visibility = $block->get('visibility')) {
-      foreach ($visibility as &$condition) {
+      foreach ($visibility as $condition_plugin_id => &$condition) {
         foreach ($condition['context_mapping'] as $key => $context) {
           if (!isset($context_service_id_map[$key])) {
-            // Skip unknown entries, so the update process itself runs through
-            // and users can fix their block placements manually OR
-            // alternatively contrib modules can run their own update functions
-            // to update mappings that they provide.
-            $message = \Drupal::translation()->translate('Encountered an unexpected context mapping key, one or more mappings could not be updated. Please manually review your block placements.');
-            $disable_block = TRUE;
+            // Remove the visibility condition for unknown context mapping
+            // entries, so the update process itself runs through and users can
+            // fix their block placements manually OR alternatively contrib
+            // modules can run their own update functions to update mappings
+            // that they provide.
+            $disabled_blocks[$block->get('id')] = $block->get('settings.label');
+            $problematic_visibility_plugins[$block->get('id')][] = $condition_plugin_id_ui_label_map[$condition_plugin_id];
+
+            unset($visibility[$condition_plugin_id]);
             continue;
           }
           $new_context_id = explode('.', $context, 2);
           $condition['context_mapping'][$key] = '@' . $context_service_id_map[$key] . ':' . $new_context_id[1];
         }
       }
-      if ($disable_block) {
+      if (isset($disabled_blocks[$block->get('id')])) {
         // This block will have an invalid context mapping service and must be
         // disabled to avoid the 'You must provide the context IDs in the
         // @{service_id}:{unqualified_context_id} format' exception.
@@ -53,9 +66,19 @@ function block_update_8001() {
 
     $block->save();
   }
+
+  if ($disabled_blocks) {
+    $message = \Drupal::translation()->translate('Encountered an unexpected context mapping key, one or more mappings could not be updated. Please manually review your visibility settings for the following blocks:');
+    $message .= '<ul>';
+    foreach ($disabled_blocks as $disabled_block_id => $disabled_block_label) {
+      $message .= '<li>' . $disabled_block_label . ' (' . \Drupal::translation()->translate('Visibility') . ': ' . implode(', ', $problematic_visibility_plugins[$disabled_block_id]) . ')</li>';
+    }
+    $message .= '</ul>';
+  }
+
   return $message;
 }
 
 /**
- * @} End of "addtogroup updates-8.0.x-beta".
+ * @} End of "addtogroup updates-8.0.0-beta".
  */
diff --git a/core/modules/block/src/Tests/Update/BlockContextMappingUpdateTest.php b/core/modules/block/src/Tests/Update/BlockContextMappingUpdateTest.php
index 1a89537..6e2b65b 100644
--- a/core/modules/block/src/Tests/Update/BlockContextMappingUpdateTest.php
+++ b/core/modules/block/src/Tests/Update/BlockContextMappingUpdateTest.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\block\Tests\Update;
 
+use Drupal\block\Entity\Block;
 use Drupal\node\Entity\Node;
 use Drupal\system\Tests\Update\UpdatePathTestBase;
 
@@ -35,7 +36,7 @@ protected function setUp() {
    */
   public function testUpdateHookN() {
     $this->runUpdates();
-    $this->assertText(t('Encountered an unexpected context mapping key, one or more mappings could not be updated. Please manually review your block placements.'));
+    $this->assertRaw('Encountered an unexpected context mapping key, one or more mappings could not be updated. Please manually review your visibility settings for the following blocks:<ul><li>User login (Visibility: Content types)</li></ul>');
 
     // Disable maintenance mode.
     \Drupal::state()->set('system.maintenance_mode', FALSE);
@@ -73,6 +74,20 @@ public function testUpdateHookN() {
 
     $this->drupalGet('node/' . $article->id());
     $this->assertNoRaw($block_title, 'Test block is not visible on a Article node as an anonymous user.');
+
+    // Check that a block with invalid context is being disabled and that it can
+    // still be edited afterward.
+    $disabled_block = Block::load('thirdtestfor2354889');
+    $this->assertFalse($disabled_block->status(), 'Block with invalid context is disabled');
+
+    $disabled_block_visibility = $disabled_block->get('visibility');
+    $this->assertTrue(!isset($disabled_block_visibility['node_type']), 'The problematic visibility condition has been removed.');
+
+    $admin_user = $this->drupalCreateUser(['administer blocks']);
+    $this->drupalLogin($admin_user);
+
+    $this->drupalGet('admin/structure/block/manage/thirdtestfor2354889');
+    $this->assertResponse('200');
   }
 
 }