Update to Drupal 8.2.4. For more information, see https://www.drupal.org/project/drupal/releases/8.2.4

core/modules/file/migration_templates/d6_file.yml

@@ -13,6 +13,9 @@ source:
     # configuration in this migration's process pipeline as an example.
     source_base_path: ''
 process:
+    # If you are using both this migration and d6_user_picture_file in a custom
+    # migration and executing migrations incrementally, it is recommended that
+    # you remove the fid mapping here to avoid potential ID conflicts.
   fid: fid
   filename: filename
   source_full_path:

core/modules/file/migration_templates/d6_upload_field.yml

@@ -20,4 +20,7 @@ process:
   cardinality: 'constants/cardinality'
   'settings/display_field': 'constants/display_field'
 destination:
-  plugin: md_entity:field_storage_config
+  plugin: entity:field_storage_config
+  dependencies:
+    module:
+      - file

core/modules/file/migration_templates/d7_file.yml

@@ -13,6 +13,8 @@ source:
     # configuration in this migration's process pipeline as an example.
     source_base_path: ''
 process:
+  # If you are using this file to build a custom migration consider removing
+  # the fid field to allow incremental migrations.
   fid: fid
   filename: filename
   source_full_path:

core/modules/file/src/Plugin/migrate/process/d6/CckFile.php

@@ -5,7 +5,6 @@ namespace Drupal\file\Plugin\migrate\process\d6;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\migrate\Plugin\MigrationInterface;
 use Drupal\migrate\MigrateExecutableInterface;
-use Drupal\migrate\MigrateSkipRowException;
 use Drupal\migrate\Plugin\MigrateProcessInterface;
 use Drupal\migrate\ProcessPluginBase;
 use Drupal\migrate\Row;
@@ -76,18 +75,7 @@ class CckFile extends ProcessPluginBase implements ContainerFactoryPluginInterfa
     // some reason -- file migration is notoriously brittle -- and we do NOT
     // want to send invalid file references into the field system (it causes
     // fatals), so return an empty item instead.
-    try {
-      $fid = $this->migrationPlugin->transform($value['fid'], $migrate_executable, $row, $destination_property);
-    }
-    // If the migration plugin completely fails its lookup process, it will
-    // throw a MigrateSkipRowException. It shouldn't, but that is being dealt
-    // with at https://www.drupal.org/node/2487568. Until that lands, return
-    // an empty item.
-    catch (MigrateSkipRowException $e) {
-      return [];
-    }
-
-    if ($fid) {
+    if ($fid = $this->migrationPlugin->transform($value['fid'], $migrate_executable, $row, $destination_property)) {
       return [
         'target_id' => $fid,
         'display' => $value['list'],