diff -u b/src/Tests/MonitoringUITest.php b/src/Tests/MonitoringUITest.php
--- b/src/Tests/MonitoringUITest.php
+++ b/src/Tests/MonitoringUITest.php
@@ -96,7 +96,6 @@
       'type' => 'article',
     ));
     $this->drupalGet('admin/config/system/monitoring/sensors/add');
-
     $this->assertFieldByName('status', TRUE);
 
     // Test creation of Node entity aggregator sensor.
@@ -124,7 +123,7 @@
     $edit['conditions[1][value]'] = '0';
     $i = 2;
     foreach ($node_fields as $field) {
-      $this->drupalPostForm(NULL, array('settings[entity_type]' => 'node'), t('Add another field'));
+      $this->drupalPostForm(NULL, array(), t('Add another field'));
       $edit['settings[verbose_fields][' . $i++ . ']'] = $field->getName();
     }
     $this->drupalPostForm(NULL, $edit, t('Save'));
@@ -134,6 +133,7 @@
     // Test details page by clicking the link in confirmation message.
     $this->assertLink(t('Node Entity Aggregator sensor'));
     $this->clickLink(t('Node Entity Aggregator sensor'));
+    $this->assertResponse(200);
     $this->assertText('Result');
     $this->assertRaw('<th>nid</th>');
     $this->assertRaw('<th>label</th>');
@@ -161,6 +161,24 @@
       $this->assertFieldByName('settings[verbose_fields][' . $i++ . ']', $field->getName());
     }
 
+    // Create a file to test.
+    $file_path = file_default_scheme() . '://test';
+    $contents = "file_put_contents().";
+    file_put_contents($file_path, $contents);
+
+    // Test if the file exist.
+    $this->assertTrue(is_file($file_path));
+
+    // Create a file entity.
+    $file = entity_create('file', array(
+      'uri' => $file_path,
+      'uid' => 1,
+    ));
+    $file->save();
+
+    // Test if the entity was created.
+    $this->assertTrue($file->id() > 0);
+
     $this->drupalGet('admin/config/system/monitoring/sensors/add');
 
     // Test creation of File entity aggregator sensor.
@@ -179,7 +197,7 @@
     $edit = array();
     $i = 2;
     foreach ($file_fields as $field) {
-      $this->drupalPostForm(NULL, array('settings[entity_type]' => 'node'), t('Add another field'));
+      $this->drupalPostForm(NULL, array(), t('Add another field'));
       $edit['settings[verbose_fields][' . $i++ . ']'] = $field->getName();
     }
     $this->drupalPostForm(NULL, $edit, t('Save'));
@@ -189,6 +207,7 @@
     // Test details page by clicking the link in confirmation message.
     $this->assertLink(t('File Entity Aggregator sensor'));
     $this->clickLink(t('File Entity Aggregator sensor'));
+    $this->assertResponse(200);
     $this->assertText('Result');
     $this->assertRaw('<th>label</th>');
     $this->assertRaw('<th>uuid</th>');
@@ -198,11 +217,11 @@
     $this->assertRaw('<th>created</th>');
 
     // Assert that the output is correct.
-    $this->assertLink($node->getTitle());
-    $this->assertLink($node->getOwner()->getUsername());
-    $this->assertText($node->uuid());
-    $this->assertText(\Drupal::service('date.formatter')->format($node->getCreatedTime(), 'short'));
-    $this->assertText($node->getChangedTime());
+    $this->assertText($file->getFilename());
+    $this->assertText($file->uuid());
+    $this->assertText($file->getSize());
+    $this->assertText($file->getMimeType());
+    $this->assertText(\Drupal::service('date.formatter')->format($file->getCreatedTime(), 'short'));
 
     $this->drupalGet('admin/config/system/monitoring/sensors/file_test_sensor');
     $i = 2;