diff --git a/modules/test/config/optional/monitoring.sensor_config.entity_aggregate_test.yml b/modules/test/config/optional/monitoring.sensor_config.entity_aggregate_test.yml
index 3c9019f..29d8ef5 100644
--- a/modules/test/config/optional/monitoring.sensor_config.entity_aggregate_test.yml
+++ b/modules/test/config/optional/monitoring.sensor_config.entity_aggregate_test.yml
@@ -15,7 +15,7 @@ settings:
     -
       field: 'type'
       value: 'page'
-  fields:
+  verbose_fields:
     - id
     - label
 thresholds:
diff --git a/src/Plugin/monitoring/SensorPlugin/DatabaseAggregatorSensorPlugin.php b/src/Plugin/monitoring/SensorPlugin/DatabaseAggregatorSensorPlugin.php
index 6995507..c074f80 100644
--- a/src/Plugin/monitoring/SensorPlugin/DatabaseAggregatorSensorPlugin.php
+++ b/src/Plugin/monitoring/SensorPlugin/DatabaseAggregatorSensorPlugin.php
@@ -230,10 +230,9 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
     $form = parent::buildConfigurationForm($form, $form_state);
 
-    $settings = $this->sensorConfig->getSettings();
     $form['table'] = array(
       '#type' => 'textfield',
-      '#default_value' => $settings['table'],
+      '#default_value' => $this->sensorConfig->getSetting('table'),
       '#maxlength' => 255,
       '#title' => t('Table'),
       '#required' => TRUE,
@@ -264,7 +263,7 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
     );
 
     // Fill the conditions table with keys and values for each condition.
-    $conditions = $settings['conditions'];
+    $conditions = $this->sensorConfig->getSetting('conditions');
 
     if (!$form_state->has('conditions_rows')) {
       $form_state->set('conditions_rows', count($conditions) + 1);
@@ -341,7 +340,7 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
     );
 
     // Fill the fields table with verbose fields to filter the output.
-    $fields = $settings['verbose_fields'];
+    $fields = $this->sensorConfig->getSetting('verbose_fields');
 
     if (!$form_state->has('fields_rows')) {
       $form_state->set('fields_rows', count($fields) + 1);
@@ -406,25 +405,23 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
     parent::submitConfigurationForm($form, $form_state);
 
-    /** @var \Drupal\monitoring\Form\SensorForm $sensor_form */
-    $sensor_form = $form_state->getFormObject();
-    /** @var \Drupal\monitoring\SensorConfigInterface $sensor_config */
-    $sensor_config = $sensor_form->getEntity();
-    $settings = $sensor_config->getSettings();
-
     // Cleanup conditions, remove empty.
-    $settings['conditions'] = [];
+    $conditions = [];
     foreach ($form_state->getValue('conditions') as $key => $condition) {
       if (!empty($condition['field'])) {
-        $settings['conditions'][] = $condition;
+        $conditions[] = $condition;
       }
     }
-    $settings['verbose_fields'] = [];
-    foreach ($form_state->getValue('verbose_fields') as $delta => $field) {
+
+    $verbose_fields = [];
+    foreach ($form_state->getValue('verbose_fields') as $field) {
       if (!empty($field)) {
-        $settings['verbose_fields'][] = $field;
+        $verbose_fields[] = $field;
       }
     }
+    $settings = $this->sensorConfig->getSettings();
+    $settings['conditions'] = $conditions;
+    $settings['verbose_fields'] = $verbose_fields;
     $this->sensorConfig->set('settings', $settings);
   }
 
@@ -498,9 +495,15 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
     /** @var \Drupal\Core\Database\Connection $database */
     $database = $this->getService('database');
     $table = $form_state->getValue(array('settings', 'table'));
+    $query = $database->select($table);
     if (!$database->schema()->tableExists($table)) {
-      $form_state->setErrorByName('settings][table', t('The table %table does not exist in the database %database', ['%table' => $table, '%database' => $database->getConnectionOptions()['database']]));
-      return;
+      try {
+        $query->range(0, 1)->execute();
+      }
+      catch (\Exception $e) {
+        $form_state->setErrorByName('settings][table', t('The table %table does not exist in the database %database', ['%table' => $table, '%database' => $database->getConnectionOptions()['database']]));
+        return;
+      }
     }
     $field_name = $form_state->getValue(array(
       'settings',
@@ -517,22 +520,25 @@ class DatabaseAggregatorSensorPlugin extends DatabaseAggregatorSensorPluginBase
     $fields = $form_state->getValue('verbose_fields');
     $new_fields = [];
     foreach ($fields as $key => $field) {
+      $query = $database->select($table);
       $field_name = $field['field'];
       if (!empty($field_name)) {
+        $query->addField($table, $field_name);
+        $new_fields[] = (array_pop($fields[$key]));
         if (!$database->schema()->fieldExists($table, $field_name)) {
-          $query = $database->select($table);
-          $query->addField($table, $field_name);
-          try{
+          try {
             $query->range(0, 1)->execute();
           }
           catch (\Exception $e) {
-            $form_state->setErrorByName('verbose_fields][' . $key . '][field', t('The specified field "%name" does not exist in table "%table".', ['%name' => $field_name, '%table' => $table]));
+
+            $form_state->setErrorByName("verbose_fields][$key][field", t('The field %field does not exist in the table "%table".', ['%field' => $new_fields[$key], '%table' => $table]));
+            unset($new_fields[$key]);
             continue;
           }
         }
-        $new_fields[] = (array_pop($fields[$key]));
       }
     }
+
     $form_state->setValue('verbose_fields', $new_fields);
   }