Update to Drupal 8.1.2. For more information, see https://www.drupal.org/project/drupal/releases/8.1.2

core/modules/forum/src/Breadcrumb/ForumBreadcrumbBuilderBase.php

@@ -17,7 +17,7 @@ use Drupal\forum\ForumManagerInterface;
  * This just holds the dependency-injected config, entity manager, and forum
  * manager objects.
  */
-abstract class ForumBreadcrumbBuilderBase  implements BreadcrumbBuilderInterface {
+abstract class ForumBreadcrumbBuilderBase implements BreadcrumbBuilderInterface {
   use StringTranslationTrait;
 
   /**

core/modules/forum/src/Form/Overview.php

@@ -10,7 +10,7 @@ use Drupal\taxonomy\Form\OverviewTerms;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
-/*
+/**
  * Provides forum overview form for the forum vocabulary.
  */
 class Overview extends OverviewTerms {

core/modules/forum/src/Plugin/Block/NewTopicsBlock.php

@@ -24,4 +24,5 @@ class NewTopicsBlock extends ForumBlockBase {
       ->orderBy('f.created', 'DESC')
       ->range(0, $this->configuration['block_count']);
   }
+
 }

core/modules/forum/src/Plugin/Validation/Constraint/ForumLeafConstraint.php

@@ -16,4 +16,5 @@ class ForumLeafConstraint extends Constraint {
 
   public $selectForum = 'Select a forum.';
   public $noLeafMessage = 'The item %forum is a forum container, not a forum. Select one of the forums below instead.';
+
 }

core/modules/forum/src/Tests/ForumBlockTest.php

@@ -176,4 +176,5 @@ class ForumBlockTest extends WebTestBase {
 
     return $topics;
   }
+
 }

core/modules/forum/src/Tests/ForumIndexTest.php

@@ -79,4 +79,5 @@ class ForumIndexTest extends WebTestBase {
     $this->drupalGet('forum/' . $tid);
     $this->assertNoText($title, 'Unpublished forum topic no longer appears on index.');
   }
+
 }

core/modules/forum/src/Tests/ForumTest.php

@@ -678,4 +678,5 @@ class ForumTest extends WebTestBase {
       $this->nids[] = $node->id();
     }
   }
+
 }

core/modules/forum/src/Tests/ForumUninstallTest.php

@@ -138,7 +138,7 @@ class ForumUninstallTest extends WebTestBase {
     // Delete all terms in the Forums vocabulary. Uninstalling the forum module
     // will fail unless this is done.
     $terms = entity_load_multiple_by_properties('taxonomy_term', array('vid' => 'forums'));
-    foreach($terms as $term) {
+    foreach ($terms as $term) {
       $term->delete();
     }