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

core/modules/history/src/Plugin/views/filter/HistoryUserTimestamp.php

@@ -18,7 +18,7 @@ use Drupal\views\Plugin\views\filter\FilterPluginBase;
 class HistoryUserTimestamp extends FilterPluginBase {
 
   // Don't display empty space where the operator would be.
-  var $no_operator = TRUE;
+  public $no_operator = TRUE;
 
   /**
    * {@inheritdoc}

core/modules/history/src/Tests/HistoryTest.php

@@ -144,4 +144,5 @@ class HistoryTest extends WebTestBase {
     $this->markNodeAsRead($nid);
     $this->assertResponse(403);
   }
+
 }

core/modules/history/src/Tests/Views/HistoryTimestampTest.php

@@ -85,4 +85,5 @@ class HistoryTimestampTest extends ViewTestBase {
     $this->executeView($view);
 
   }
+
 }