core/modules/rdf/rdf.module                        |  3 ++-
 .../src/Plugin/rest/resource/EntityResource.php    | 18 ++++++++++----
 core/modules/rest/src/Tests/ResourceTest.php       | 28 ++++++++++++++++++++++
 3 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/core/modules/rdf/rdf.module b/core/modules/rdf/rdf.module
index 33a3e92..ceda758 100644
--- a/core/modules/rdf/rdf.module
+++ b/core/modules/rdf/rdf.module
@@ -233,8 +233,9 @@ function rdf_comment_storage_load($comments) {
     $created_mapping = rdf_get_mapping('comment', $comment->bundle())
       ->getPreparedFieldMapping('created');
     $comment->rdf_data['date'] = rdf_rdfa_attributes($created_mapping, $comment->get('created')->first()->toArray());
+    /** @var \Drupal\Core\Entity\EntityInterface $entity */
     $entity = $comment->getCommentedEntity();
-    $comment->rdf_data['entity_uri'] = $entity->url();
+    $comment->rdf_data['entity_uri'] = $entity->toUrl()->toString(TRUE)->getGeneratedUrl();
     if ($comment->hasParentComment()) {
       $comment->rdf_data['pid_uri'] = $comment->getParentComment()->url();
     }
diff --git a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
index 34b0bda..2d96603 100644
--- a/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
+++ b/core/modules/rest/src/Plugin/rest/resource/EntityResource.php
@@ -144,13 +144,21 @@ public function patch(EntityInterface $original_entity, EntityInterface $entity
     }
 
     // Overwrite the received properties.
-    $langcode_key = $entity->getEntityType()->getKey('langcode');
+    $entity_keys = array_values($entity->getEntityType()->getKeys());
     foreach ($entity->_restSubmittedFields as $field_name) {
       $field = $entity->get($field_name);
-      // It is not possible to set the language to NULL as it is automatically
-      // re-initialized. As it must not be empty, skip it if it is.
-      if ($field_name == $langcode_key && $field->isEmpty()) {
-        continue;
+
+      // Entity key fields need special treatment.
+      if (in_array($field_name, $entity_keys)) {
+        // Unchanged Values for entity keys same don't need access checking.
+        if ($original_entity->get($field_name)->getValue() === $entity->get($field_name)->getValue()) {
+          continue;
+        }
+        // It is not possible to set the language to NULL as it is automatically
+        // re-initialized. As it must not be empty, skip it if it is.
+        else if (isset($entity_keys['langcode']) && $field_name === $entity_keys['langcode'] && $field->isEmpty()) {
+          continue;
+        }
       }
 
       if (!$original_entity->get($field_name)->access('edit')) {
diff --git a/core/modules/rest/src/Tests/ResourceTest.php b/core/modules/rest/src/Tests/ResourceTest.php
index c20b751..50521cb 100644
--- a/core/modules/rest/src/Tests/ResourceTest.php
+++ b/core/modules/rest/src/Tests/ResourceTest.php
@@ -6,6 +6,8 @@
  */
 
 namespace Drupal\rest\Tests;
+
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\user\Entity\Role;
 
@@ -121,4 +123,30 @@ public function testUriPaths() {
     }
   }
 
+  /**
+   * Tests that a resource with a missing plugin does not cause an exception.
+   */
+  public function testMissingPlugin() {
+    $settings = array(
+      'entity:nonexisting' => array(
+        'GET' => array(
+          'supported_formats' => array(
+            'hal_json',
+          ),
+        ),
+      ),
+    );
+
+    try {
+      // Attempt to enable the resource.
+      $this->config->set('resources', $settings);
+      $this->config->save();
+      $this->rebuildCache();
+      $this->pass('rest.settings referencing a missing REST resource plugin does not cause an exception.');
+    }
+    catch (PluginNotFoundException $e) {
+      $this->fail('rest.settings referencing a missing REST resource plugin caused an exception.');
+    }
+  }
+
 }