diff -u b/core/modules/migrate/src/Plugin/migrate/destination/EntityFile.php b/core/modules/migrate/src/Plugin/migrate/destination/EntityFile.php
--- b/core/modules/migrate/src/Plugin/migrate/destination/EntityFile.php
+++ b/core/modules/migrate/src/Plugin/migrate/destination/EntityFile.php
@@ -7,12 +7,12 @@
 
 namespace Drupal\migrate\Plugin\migrate\destination;
 
+use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\StreamWrapper\LocalStream;
 use Drupal\Core\StreamWrapper\StreamWrapperManagerInterface;
-use Drupal\Core\StringTranslation\TranslationInterface;
 use Drupal\migrate\Entity\MigrationInterface;
 use Drupal\migrate\Row;
 use Drupal\migrate\MigrateException;
@@ -41,7 +41,7 @@
   /**
    * {@inheritdoc}
    */
-  public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, TranslationInterface $translator, EntityStorageInterface $storage, array $bundles, EntityManagerInterface $entity_manager, StreamWrapperManagerInterface $stream_wrappers, FileSystemInterface $file_system) {
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, EntityStorageInterface $storage, array $bundles, EntityManagerInterface $entity_manager, StreamWrapperManagerInterface $stream_wrappers, FileSystemInterface $file_system) {
     $configuration += array(
       'source_base_path' => '',
       'source_path_property' => 'filepath',
@@ -51,7 +51,6 @@
     );
     parent::__construct($configuration, $plugin_id, $plugin_definition, $migration, $storage, $bundles, $entity_manager);
 
-    $this->stringTranslation = $translator;
     $this->streamWrapperManager = $stream_wrappers;
     $this->fileSystem = $file_system;
   }
@@ -66,7 +65,6 @@
       $plugin_id,
       $plugin_definition,
       $migration,
-      $container->get('string_translation'),
       $container->get('entity.manager')->getStorage($entity_type),
       array_keys($container->get('entity.manager')->getBundleInfo($entity_type)),
       $container->get('entity.manager'),
@@ -85,7 +83,7 @@
 
     // Ensure the source file exists, if it's a local URI or path.
     if ($this->isLocalUri($source) && !file_exists($source)) {
-      throw new MigrateException($this->t('File %source does not exist.', ['%source' => $source]));
+      throw new MigrateException(SafeMarkup::format('File %source does not exist.', ['%source' => $source]));
     }
 
     // If the start and end file is exactly the same, there is nothing to do.
@@ -101,7 +99,7 @@
         $success = $this->writeFile($source, $destination, $replace);
       }
       else {
-        throw new MigrateException($this->t('Could not create directory %dir', ['%dir' => $dir]));
+        throw new MigrateException(SafeMarkup::format('Could not create directory %dir', ['%dir' => $dir]));
       }
     }
 
@@ -109,7 +107,7 @@
       return parent::import($row, $old_destination_id_values);
     }
     else {
-      throw new MigrateException($this->t('File %source could not be copied to %destination.', ['%source' => $source, '%destination' => $destination]));
+      throw new MigrateException(SafeMarkup::format('File %source could not be copied to %destination.', ['%source' => $source, '%destination' => $destination]));
     }
   }
 
diff -u b/core/modules/migrate/tests/src/Unit/destination/EntityFileTest.php b/core/modules/migrate/tests/src/Unit/destination/EntityFileTest.php
--- b/core/modules/migrate/tests/src/Unit/destination/EntityFileTest.php
+++ b/core/modules/migrate/tests/src/Unit/destination/EntityFileTest.php
@@ -39,7 +39,6 @@
   public function setUp() {
     parent::setUp();
     $this->destination = new TestEntityFile([]);
-    $this->destination->stringTranslation = \Drupal::getContainer()->get('string_translation');
     $this->destination->streamWrapperManager = \Drupal::getContainer()->get('stream_wrapper_manager');
     $this->destination->fileSystem = \Drupal::getContainer()->get('file_system');
 
@@ -141,11 +140,6 @@
   public $configuration;
 
   /**
-   * @var \Drupal\Core\StringTranslation\TranslationInterface
-   */
-  public $stringTranslation;
-
-  /**
    * @var \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface
    */
   public $streamWrapperManager;
only in patch2:
unchanged:
--- a/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php
+++ b/core/modules/migrate_drupal/src/Tests/d6/MigrateFileTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\migrate_drupal\Tests\d6;
 
 use Drupal\Component\Utility\Random;
+use Drupal\file\FileInterface;
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Tests\MigrateDumpAlterInterface;
 use Drupal\migrate_drupal\Tests\d6\MigrateDrupal6TestBase;
@@ -60,10 +61,15 @@ protected function setUp() {
   public function testFiles() {
     /** @var \Drupal\file\FileInterface $file */
     $file = entity_load('file', 1);
-    $this->assertIdentical('Image1.png', $file->getFilename());
-    $this->assertIdentical('39325', $file->getSize());
-    $this->assertIdentical('public://image-1.png', $file->getFileUri());
-    $this->assertIdentical('image/png', $file->getMimeType());
+    if ($file instanceof FileInterface) {
+      $this->assertIdentical('Image1.png', $file->getFilename());
+      $this->assertIdentical('39325', $file->getSize());
+      $this->assertIdentical('public://image-1.png', $file->getFileUri());
+      $this->assertIdentical('image/png', $file->getMimeType());
+    }
+    else {
+      $this->fail('File 1 does not exist.');
+    }
     // It is pointless to run the second half from MigrateDrupal6Test.
     if (empty($this->standalone)) {
       return;
@@ -92,11 +98,21 @@ public function testFiles() {
     $executable->import();
 
     $file = entity_load('file', 2);
-    $this->assertIdentical('public://core/modules/simpletest/files/image-2.jpg', $file->getFileUri());
+    if ($file instanceof FileInterface) {
+      $this->assertIdentical('public://core/modules/simpletest/files/image-2.jpg', $file->getFileUri());
+    }
+    else {
+      $this->fail('File 2 does not exist.');
+    }
 
     // Ensure that a temporary file has been migrated.
     $file = entity_load('file', 6);
-    $this->assertIdentical('temporary://' . static::getUniqueFilename(), $file->getFileUri());
+    if ($file instanceof FileInterface) {
+      $this->assertIdentical('temporary://' . static::getUniqueFilename(), $file->getFileUri());
+    }
+    else {
+      $this->fail('File 6 does not exist.');
+    }
   }
 
   /**