diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index bbf5c43..96f810e 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -9,13 +9,13 @@
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\Language;
+use Drupal\Core\ParamConverter\ParamNotConvertedException;
 use Drupal\Core\Routing\RequestHelper;
 use Drupal\Core\Template\Attribute;
 use Drupal\menu_link\Entity\MenuLink;
 use Drupal\menu_link\MenuLinkStorageController;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\Routing\Route;
 
 /**
@@ -934,7 +934,7 @@ function menu_item_route_access(Route $route, $href, &$map, Request $request = N
   try {
     $request->attributes->add(\Drupal::service('router')->matchRequest($request));
   }
-  catch (NotFoundHttpException $e) {
+  catch (ParamNotConvertedException $e) {
     return FALSE;
   }
 
diff --git a/core/modules/config_translation/lib/Drupal/config_translation/Controller/ConfigTranslationController.php b/core/modules/config_translation/lib/Drupal/config_translation/Controller/ConfigTranslationController.php
index 03c2a20..9c65218 100644
--- a/core/modules/config_translation/lib/Drupal/config_translation/Controller/ConfigTranslationController.php
+++ b/core/modules/config_translation/lib/Drupal/config_translation/Controller/ConfigTranslationController.php
@@ -13,12 +13,12 @@
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\ParamConverter\ParamNotConvertedException;
 use Drupal\Core\PathProcessor\InboundPathProcessorInterface;
 use Drupal\Core\Session\AccountInterface;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Component\Routing\Exception\ResourceNotFoundException;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
 
@@ -252,7 +252,7 @@ protected function getRequestForPath(Request $request, $path) {
       $route_request->attributes->add($this->router->matchRequest($route_request));
       return $route_request;
     }
-    catch (NotFoundHttpException $e) {
+    catch (ParamNotConvertedException $e) {
       return NULL;
     }
     catch (ResourceNotFoundException $e) {
diff --git a/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php b/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
index 827c06f..3c6dbcd 100644
--- a/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
+++ b/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
@@ -44,7 +44,9 @@ public function access(Route $route, Request $request, AccountInterface $account
     // @todo Request argument validation and object loading should happen
     //   elsewhere in the request processing pipeline:
     //   http://drupal.org/node/1798214.
-    $this->validateAndUpcastRequestAttributes($request);
+    if (!$this->validateAndUpcastRequestAttributes($request)) {
+      return static::KILL;
+    }
 
     return $this->accessEditEntity($request->attributes->get('entity'), $account)  ? static::ALLOW : static::DENY;
   }
@@ -65,14 +67,16 @@ protected function validateAndUpcastRequestAttributes(Request $request) {
       $entity_id = $entity;
       $entity_type = $request->attributes->get('entity_type');
       if (!$entity_type || !$this->entityManager->getDefinition($entity_type)) {
-        throw new NotFoundHttpException();
+        return FALSE;
       }
       $entity = $this->entityManager->getStorageController($entity_type)->load($entity_id);
       if (!$entity) {
-        throw new NotFoundHttpException();
+        return FALSE;
       }
       $request->attributes->set('entity', $entity);
     }
+
+    return TRUE;
   }
 
 }
diff --git a/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php b/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
index 9de7347..50aaf64 100644
--- a/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
+++ b/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
@@ -12,7 +12,6 @@
 use Drupal\Core\Session\AccountInterface;
 use Symfony\Component\Routing\Route;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Drupal\Core\Entity\EntityInterface;
 
 /**
@@ -44,7 +43,9 @@ public function access(Route $route, Request $request, AccountInterface $account
     // @todo Request argument validation and object loading should happen
     //   elsewhere in the request processing pipeline:
     //   http://drupal.org/node/1798214.
-    $this->validateAndUpcastRequestAttributes($request);
+    if (!$this->validateAndUpcastRequestAttributes($request)) {
+      return static::KILL;
+    }
 
     return $this->accessEditEntityField($request->attributes->get('entity'), $request->attributes->get('field_name'))  ? static::ALLOW : static::DENY;
   }
@@ -65,11 +66,11 @@ protected function validateAndUpcastRequestAttributes(Request $request) {
       $entity_id = $entity;
       $entity_type = $request->attributes->get('entity_type');
       if (!$entity_type || !$this->entityManager->getDefinition($entity_type)) {
-        throw new NotFoundHttpException();
+        return FALSE;
       }
       $entity = $this->entityManager->getStorageController($entity_type)->load($entity_id);
       if (!$entity) {
-        throw new NotFoundHttpException();
+        return FALSE;
       }
       $request->attributes->set('entity', $entity);
     }
@@ -77,12 +78,14 @@ protected function validateAndUpcastRequestAttributes(Request $request) {
     // Validate the field name and language.
     $field_name = $request->attributes->get('field_name');
     if (!$field_name || !$entity->hasField($field_name)) {
-      throw new NotFoundHttpException();
+      return FALSE;
     }
     $langcode = $request->attributes->get('langcode');
     if (!$langcode || !$entity->hasTranslation($langcode)) {
-      throw new NotFoundHttpException();
+      return FALSE;
     }
+
+    return TRUE;
   }
 
 }
diff --git a/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityAccessCheckTest.php b/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityAccessCheckTest.php
index 0d5ca57..9e8d050 100644
--- a/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityAccessCheckTest.php
+++ b/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityAccessCheckTest.php
@@ -117,8 +117,6 @@ public function testAccess(EntityInterface $entity, $expected_result) {
 
   /**
    * Tests the access method with an undefined entity type.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithUndefinedEntityType() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity' => 'TRUE'));
@@ -131,13 +129,11 @@ public function testAccessWithUndefinedEntityType() {
       ->will($this->returnValue(NULL));
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with a non existing entity.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithNotExistingEntity() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -156,7 +152,7 @@ public function testAccessWithNotExistingEntity() {
       ->will($this->returnValue(NULL));
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
 }
diff --git a/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityFieldAccessCheckTest.php b/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityFieldAccessCheckTest.php
index b9c847d..0791249 100644
--- a/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityFieldAccessCheckTest.php
+++ b/core/modules/edit/tests/Drupal/edit/Tests/Access/EditEntityFieldAccessCheckTest.php
@@ -144,8 +144,6 @@ public function testAccess(EntityInterface $entity, FieldInterface $field = NULL
 
   /**
    * Tests the access method with an undefined entity type.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithUndefinedEntityType() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -158,13 +156,11 @@ public function testAccessWithUndefinedEntityType() {
       ->will($this->returnValue(NULL));
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with a non existing entity.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithNotExistingEntity() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -183,13 +179,11 @@ public function testAccessWithNotExistingEntity() {
       ->will($this->returnValue(NULL));
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with a forgotten passed field_name.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithNotPassedFieldName() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -198,13 +192,11 @@ public function testAccessWithNotPassedFieldName() {
     $request->attributes->set('entity', $this->createMockEntity());
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with a non existing field.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithNonExistingField() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -214,13 +206,11 @@ public function testAccessWithNonExistingField() {
     $request->attributes->set('field_name', 'not_valid');
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with a forgotten passed language.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithNotPassedLanguage() {
     $route = new Route('/edit/form/test_entity/1/body/und/full', array(), array('_access_edit_entity_field' => 'TRUE'));
@@ -230,13 +220,11 @@ public function testAccessWithNotPassedLanguage() {
     $request->attributes->set('field_name', 'valid');
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
    * Tests the access method with an invalid language.
-   *
-   * @expectedException \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
   public function testAccessWithInvalidLanguage() {
     $entity = $this->createMockEntity();
@@ -253,7 +241,7 @@ public function testAccessWithInvalidLanguage() {
     $request->attributes->set('langcode', 'xx-lolspeak');
 
     $account = $this->getMock('Drupal\Core\Session\AccountInterface');
-    $this->editAccessCheck->access($route, $request, $account);
+    $this->assertSame(AccessCheckInterface::KILL, $this->editAccessCheck->access($route, $request, $account));
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
index 4ab853c..f39a1a5 100644
--- a/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
+++ b/core/modules/system/lib/Drupal/system/PathBasedBreadcrumbBuilder.php
@@ -12,10 +12,10 @@
 use Drupal\Core\Controller\TitleResolverInterface;
 use Drupal\Core\Access\AccessManager;
 use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\ParamConverter\ParamNotConvertedException;
 use Drupal\Core\PathProcessor\InboundPathProcessorInterface;
 use Drupal\Component\Utility\Unicode;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\Routing\Matcher\RequestMatcherInterface;
 use Symfony\Component\Routing\Exception\ResourceNotFoundException;
@@ -192,7 +192,7 @@ protected function getRequestForPath($path, array $exclude) {
       $request->attributes->add($this->router->matchRequest($request));
       return $request;
     }
-    catch (NotFoundHttpException $e) {
+    catch (ParamNotConvertedException $e) {
       return NULL;
     }
     catch (ResourceNotFoundException $e) {
diff --git a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
index 25d3de0..2ce0f87 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
@@ -149,6 +149,20 @@ public function testUrlGeneratorFront() {
   }
 
   /**
+   * Tests that a page trying to match a path will succeed.
+   */
+  public function testRouterMatching() {
+    $this->drupalGet('router_test/test14/1');
+    $this->assertResponse(200);
+    $this->assertText('User route "user.view" was matched.');
+
+    // Try to match a route for a non-existent user.
+    $this->drupalGet('router_test/test14/2');
+    $this->assertResponse(200);
+    $this->assertText('Route not matched.');
+  }
+
+  /**
    * Tests the user account on the DIC.
    */
   public function testUserAccount() {
diff --git a/core/modules/system/tests/modules/router_test_directory/lib/Drupal/router_test/TestControllers.php b/core/modules/system/tests/modules/router_test_directory/lib/Drupal/router_test/TestControllers.php
index 86342d5..0db6826 100644
--- a/core/modules/system/tests/modules/router_test_directory/lib/Drupal/router_test/TestControllers.php
+++ b/core/modules/system/tests/modules/router_test_directory/lib/Drupal/router_test/TestControllers.php
@@ -7,6 +7,9 @@
 
 namespace Drupal\router_test;
 
+use Drupal\Core\ParamConverter\ParamNotConvertedException;
+use Drupal\user\UserInterface;
+use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\HttpFoundation\Response;
 
 /**
@@ -50,4 +53,17 @@ public function test8() {
     return new Response('test8');
   }
 
+  public function test9($uid) {
+    $text = 'Route not matched.';
+    try {
+      $match = \Drupal::service('router')->match('/user/' . $uid);
+      if (isset($match['user']) && $match['user'] instanceof UserInterface) {
+        $text = sprintf('User route "%s" was matched.', $match[RouteObjectInterface::ROUTE_NAME]);
+      }
+    }
+    catch (ParamNotConvertedException $e) {
+    }
+    return new Response($text);
+  }
+
 }
diff --git a/core/modules/system/tests/modules/router_test_directory/router_test.routing.yml b/core/modules/system/tests/modules/router_test_directory/router_test.routing.yml
index 7ad0607..d0460a1 100644
--- a/core/modules/system/tests/modules/router_test_directory/router_test.routing.yml
+++ b/core/modules/system/tests/modules/router_test_directory/router_test.routing.yml
@@ -86,3 +86,10 @@ router_test.13:
   defaults:
     _content: '\Drupal\router_test\TestContent::testAccount'
 
+router_test.14:
+  path: '/router_test/test14/{uid}'
+  requirements:
+    _access: 'TRUE'
+  defaults:
+    _controller: '\Drupal\router_test\TestControllers::test9'
+