diff -u b/core/modules/language/src/HttpKernel/PathProcessorLanguage.php b/core/modules/language/src/HttpKernel/PathProcessorLanguage.php
--- b/core/modules/language/src/HttpKernel/PathProcessorLanguage.php
+++ b/core/modules/language/src/HttpKernel/PathProcessorLanguage.php
@@ -179,7 +179,6 @@
    * Resets the collected processors instances.
    */
   public function reset() {
-    debug('reset path processor language');
     $this->processors = array();
   }
 
diff -u b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
--- b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
+++ b/core/modules/language/src/Plugin/LanguageNegotiation/LanguageNegotiationContentEntity.php
@@ -52,11 +52,11 @@
   protected $contentEntityPaths;
 
   /**
-   * Checks criteria for outbound processing.
+   * Static cache for the language negotiation order check.
    *
    * @var bool
    */
-  protected $checkLanguageNegotiationOrder;
+  protected $languageNegotiationOrderCheckResult;
 
   /**
    * The route provider.
@@ -187,7 +187,7 @@
    *   TRUE if the configuration condition is met, FALSE otherwise.
    */
   protected function checkLanguageNegotiationOrder() {
-    if (!isset($this->checkLanguageNegotiationOrder)) {
+    if (!isset($this->languageNegotiationOrderCheckResult)) {
       // Only run if the LanguageNegotiationContentEntity outbound function is
       // being executed before the outbound function of LanguageNegotiationUrl.
       $enabled_methods_content = $this->config->get('language.types')->get('negotiation.language_content.enabled') ?: [];
@@ -195,7 +195,7 @@
       // Check if the content language is configured to be dependent on the
       // url negotiator directly or indirectly over the interface negotiator.
       if (isset($enabled_methods_content[LanguageNegotiationUrl::METHOD_ID]) && ($enabled_methods_content[static::METHOD_ID] > $enabled_methods_content[LanguageNegotiationUrl::METHOD_ID])) {
-        $this->checkLanguageNegotiationOrder = FALSE;
+        $this->languageNegotiationOrderCheckResult = FALSE;
       }
       else {
         $check_interface_method = FALSE;
@@ -211,11 +211,11 @@
           $check_against_weight = isset($enabled_methods_content[LanguageNegotiationUrl::METHOD_ID]) ? $enabled_methods_content[LanguageNegotiationUrl::METHOD_ID] : PHP_INT_MAX;
         }
 
-        $this->checkLanguageNegotiationOrder = $enabled_methods_content[static::METHOD_ID] < $check_against_weight;
+        $this->languageNegotiationOrderCheckResult = $enabled_methods_content[static::METHOD_ID] < $check_against_weight;
       }
     }
 
-    return $this->checkLanguageNegotiationOrder;
+    return $this->languageNegotiationOrderCheckResult;
   }
 
   /**
only in patch2:
unchanged:
--- a/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php
+++ b/core/tests/Drupal/Tests/Core/PathProcessor/PathProcessorTest.php
@@ -150,11 +150,16 @@ function testProcessInbound() {
     $current_user = $this->getMockBuilder('Drupal\Core\Session\AccountInterface')
       ->getMock();
 
+    // Create a config event subscriber stub.
+    $config_subscriber = $this->getMockBuilder('Drupal\language\EventSubscriber\ConfigSubscriber')
+      ->disableOriginalConstructor()
+      ->getMock();
+
     // Create the processors.
     $alias_processor = new PathProcessorAlias($alias_manager);
     $decode_processor = new PathProcessorDecode();
     $front_processor = new PathProcessorFront($config_factory_stub);
-    $language_processor = new PathProcessorLanguage($config_factory_stub, $this->languageManager, $negotiator, $current_user);
+    $language_processor = new PathProcessorLanguage($config_factory_stub, $this->languageManager, $negotiator, $current_user, $config_subscriber);
 
     // First, test the processor manager with the processors in the incorrect
     // order. The alias processor will run before the language processor, meaning