diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index 179206b..188ac80 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -448,16 +448,22 @@ class Index extends ConfigEntityBase implements IndexInterface {
    * {@inheritdoc}
    */
   public function getProcessors($only_enabled = TRUE) {
+    if (!$only_enabled) {
+      return $this->loadProcessors();
+    }
+
+    if (!is_null($this->processorInstances)) {
+      return $this->processorInstances;
+    }
+
     $processors = $this->loadProcessors();
 
     // Filter processors by status if required. Enabled processors are those
     // which have settings in the "processors" option.
-    if ($only_enabled) {
-      $processors_settings = $this->processor_settings;
-      $processors = array_intersect_key($processors, $processors_settings);
-    }
+    $processors_settings = $this->processor_settings;
+    $this->processorInstances = array_intersect_key($processors, $processors_settings);
 
-    return $processors;
+    return $this->processorInstances;
   }
 
   /**
@@ -496,13 +502,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
    * {@inheritdoc}
    */
   public function addProcessor(ProcessorInterface $processor) {
-    $this->processor_settings[$processor->getPluginId()] = array(
-      'plugin_id' => $processor->getPluginId(),
-      'settings' => $processor->getConfiguration(),
-    );
-
-    // Reset processors canonical storage.
-    $this->processorInstances = NULL;
+    $this->processorInstances[$processor->getPluginId()] = $processor;
 
     return $this;
   }
@@ -511,10 +511,12 @@ class Index extends ConfigEntityBase implements IndexInterface {
    * {@inheritdoc}
    */
   public function removeProcessor($processor_id) {
-    unset($this->processor_settings[$processor_id]);
-
-    // Reset processors canonical storage.
-    $this->processorInstances = NULL;
+    // Make sure the processorInstances are loaded before trying to remove a
+    // plugin from them.
+    if (is_null($this->processorInstances)) {
+      $this->getProcessors();
+    }
+    unset($this->processorInstances[$processor_id]);
 
     return $this;
   }
@@ -526,30 +528,30 @@ class Index extends ConfigEntityBase implements IndexInterface {
    *   The loaded processors, keyed by processor ID.
    */
   protected function loadProcessors() {
-    if (is_null($this->processorInstances)) {
-      /** @var $processor_plugin_manager \Drupal\search_api\Processor\ProcessorPluginManager */
-      $processor_plugin_manager = \Drupal::service('plugin.manager.search_api.processor');
-      $processor_settings = $this->processor_settings;
-
-      foreach ($processor_plugin_manager->getDefinitions() as $name => $processor_definition) {
-        if (class_exists($processor_definition['class']) && empty($this->processorInstances[$name])) {
-          // Create our settings for this processor.
-          $settings = empty($processor_settings[$name]['settings']) ? array() : $processor_settings[$name]['settings'];
-          $settings['index'] = $this;
-
-          /** @var $processor \Drupal\search_api\Processor\ProcessorInterface */
-          $processor = $processor_plugin_manager->createInstance($name, $settings);
-          if ($processor->supportsIndex($this)) {
-            $this->processorInstances[$name] = $processor;
-          }
-        }
-        elseif (!class_exists($processor_definition['class'])) {
-          \Drupal::logger('search_api')->warning('Processor @id specifies a non-existing @class.', array('@id' => $name, '@class' => $processor_definition['class']));
+    $processor_instances = array();
+
+    /** @var $processor_plugin_manager \Drupal\search_api\Processor\ProcessorPluginManager */
+    $processor_plugin_manager = \Drupal::service('plugin.manager.search_api.processor');
+    $processor_settings = $this->processor_settings;
+
+    foreach ($processor_plugin_manager->getDefinitions() as $name => $processor_definition) {
+      if (class_exists($processor_definition['class']) && empty($processor_instances[$name])) {
+        // Create our settings for this processor.
+        $settings = empty($processor_settings[$name]['settings']) ? array() : $processor_settings[$name]['settings'];
+        $settings['index'] = $this;
+
+        /** @var $processor \Drupal\search_api\Processor\ProcessorInterface */
+        $processor = $processor_plugin_manager->createInstance($name, $settings);
+        if ($processor->supportsIndex($this)) {
+          $processor_instances[$name] = $processor;
         }
       }
+      elseif (!class_exists($processor_definition['class'])) {
+        \Drupal::logger('search_api')->warning('Processor @id specifies a non-existing @class.', array('@id' => $name, '@class' => $processor_definition['class']));
+      }
     }
 
-    return $this->processorInstances;
+    return $processor_instances;
   }
 
   /**
@@ -1004,6 +1006,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
 
     // We first have to check for locked processors, otherwise their
     // preIndexSave() methods might not be called in the next step.
+    $this->processor_settings = array();
     foreach ($this->getProcessors(FALSE) as $processor_id => $processor) {
       if ($processor->isLocked() && !isset($this->processor_settings[$processor_id])) {
         $this->processor_settings[$processor_id] = array(
@@ -1013,6 +1016,19 @@ class Index extends ConfigEntityBase implements IndexInterface {
       }
     }
 
+    foreach ($this->getProcessors() as $processor_id => $processor) {
+      $this->processor_settings[$processor_id] = array(
+        'plugin_id' => $processor_id,
+        'settings' => $processor->getConfiguration(),
+      );
+    }
+
+    // Reset the canonical representation of the processors by running
+    // ::getProcessors() again here after resetting them back to NULL. This is
+    // only needed when creating a new Index.
+    $this->processorInstances = NULL;
+    $this->getProcessors();
+
     // Add tracker settings.
     $this->tracker_settings = array(
       $this->getTrackerId() => array(
@@ -1460,6 +1476,8 @@ class Index extends ConfigEntityBase implements IndexInterface {
     // according to plugin type, unfortunately.
     // First, remove plugins that need to be removed.
     $this->processor_settings = array_intersect_key($this->processor_settings, $all_plugins['processors']);
+    $this->processorInstances = array_intersect_key($this->processorInstances, $all_plugins['processors']);
+
     $new_datasources = array();
     foreach ($all_plugins['datasources'] as $plugin_id => $settings) {
       $new_datasources[$plugin_id] = array(
diff --git a/src/Tests/IntegrationTest.php b/src/Tests/IntegrationTest.php
index 9ea4230..cd098d1 100644
--- a/src/Tests/IntegrationTest.php
+++ b/src/Tests/IntegrationTest.php
@@ -123,6 +123,7 @@ class IntegrationTest extends WebTestBase {
         'datasources[]' => array('entity:node'),
       );
     $this->drupalPostForm(NULL, $edit, $this->t('Save'));
+    $this->assertResponse(200);
     $this->assertText($this->t('The index was successfully saved.'));
     $this->assertText($this->t('Successfully tracked @count items for this index.', array('@count' => 2)));
     $this->assertEqual(2, $this->countTrackedItems());
diff --git a/src/Tests/Processor/ProcessorIntegrationTest.php b/src/Tests/Processor/ProcessorIntegrationTest.php
index b2ab842..2610fda 100644
--- a/src/Tests/Processor/ProcessorIntegrationTest.php
+++ b/src/Tests/Processor/ProcessorIntegrationTest.php
@@ -34,7 +34,7 @@ class ProcessorIntegrationTest extends WebTestBase {
       'status' => 1,
       'datasource_settings' => array(
         'entity:node' => array(
-          'plugin_id' => 'entity:user',
+          'plugin_id' => 'entity:node',
           'settings' => array(),
         ),
       ),
diff --git a/tests/src/Kernel/ServerTaskTest.php b/tests/src/Kernel/ServerTaskTest.php
index a3faf29..8fe8e7a 100644
--- a/tests/src/Kernel/ServerTaskTest.php
+++ b/tests/src/Kernel/ServerTaskTest.php
@@ -97,7 +97,7 @@ class ServerTaskTest extends KernelTestBase {
           'settings' => array(),
         ),
       ),
-      'tracker' => array(
+      'tracker_settings' => array(
         'default' => array(
           'plugin_id' => 'default',
           'settings' => array(),