diff -u b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
--- b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
+++ b/core/modules/migrate/src/Plugin/migrate/id_map/Sql.php
@@ -172,8 +172,7 @@
       $plugin_id,
       $plugin_definition,
       $migration,
-      $container->get('event_dispatcher'),
-      $container->get('plugin.manager.migration')
+      $container->get('event_dispatcher')
     );
   }
 
diff -u b/core/modules/migrate/tests/src/Unit/Plugin/migrate/destination/EntityContentBaseTest.php b/core/modules/migrate/tests/src/Unit/Plugin/migrate/destination/EntityContentBaseTest.php
--- b/core/modules/migrate/tests/src/Unit/Plugin/migrate/destination/EntityContentBaseTest.php
+++ b/core/modules/migrate/tests/src/Unit/Plugin/migrate/destination/EntityContentBaseTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\Tests\migrate\Unit\Plugin\migrate\destination;
 
 use Drupal\Core\Entity\ContentEntityInterface;
-use Drupal\Core\Entity\ContentEntityType;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
reverted:
--- b/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php
+++ a/core/modules/migrate_drupal/tests/src/Kernel/MigrateDrupalTestBase.php
@@ -3,8 +3,6 @@
 namespace Drupal\Tests\migrate_drupal\Kernel;
 
 use Drupal\Core\Database\Database;
-use Drupal\migrate\Audit\AuditResult;
-use Drupal\migrate\Audit\IdAuditor;
 use Drupal\Tests\migrate\Kernel\MigrateTestBase;
 
 /**
diff -u b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
--- b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
+++ b/core/modules/migrate_drupal_ui/src/Form/MigrateUpgradeForm.php
@@ -494,20 +494,18 @@
     $results = (new IdAuditor())->auditMultiple($migrations);
 
     /** @var \Drupal\migrate\Audit\AuditResult $result */
-    foreach ($results as $migration_id => $result) {
+    foreach ($results as $result) {
       // If the migration passed the audit, we don't need to do anything.
       if ($result->passed()) {
         continue;
       }
 
       $destination = $result->getMigration()->getDestinationPlugin();
-      $definition = $destination->getPluginDefinition();
-
       if ($destination instanceof EntityContentBase && $destination->isTranslationDestination()) {
-        $translated_content_conflicts[$migration_id] = $definition['label'];
+        $translated_content_conflicts[] = $result;
       }
       else {
-        $content_conflicts[$migration_id] = $definition['label'];
+        $content_conflicts[] = $result;
       }
     }
     if (empty($content_conflicts) && empty($translated_content_conflicts)) {
@@ -523,8 +521,13 @@
     $form['actions']['submit']['#submit'] = ['::submitConfirmIdConflictForm'];
     $form['actions']['submit']['#value'] = $this->t('I acknowledge I may lose data, continue anyway.');
 
-    $form = $this->conflictsForm($form, $form_state, $content_conflicts);
-    return $this->i18nWarningForm($form, $form_state, $translated_content_conflicts);
+    if ($content_conflicts) {
+      $form = $this->conflictsForm($form, $form_state, $content_conflicts);
+    }
+    if ($translated_content_conflicts) {
+      $form = $this->i18nWarningForm($form, $form_state, $translated_content_conflicts);
+    }
+    return $form;
   }
 
   /**
@@ -534,54 +537,70 @@
    *   An associative array containing the structure of the form.
    * @param \Drupal\Core\Form\FormStateInterface $form_state
    *   The current state of the form.
-   * @param array $content_conflicts
-   *   The conflicted migration labels.
+   * @param \Drupal\migrate\Audit\AuditResult[] $conflicts
+   *   The failing audit results.
    *
    * @return array
    *   The form structure.
    */
-  protected function conflictsForm(array &$form, FormStateInterface $form_state, $content_conflicts) {
-    if (empty($content_conflicts)) {
-      return $form;
-    }
-
+  protected function conflictsForm(array &$form, FormStateInterface $form_state, array $conflicts) {
     $form['warning']['#markup'] .= '<p>' . $this->t('Upgrades work on clean and empty new installs of Drupal 8. However, it looks like you have content in your site that is unknown to the migrate system; perhaps manually added. These new entities <strong>may be overwritten</strong> if you run this upgrade. For more information, see the online handbook entry for <a target="_blank" href=":id-conflicts-handbook">handling migration conflicts</a>.', [':id-conflicts-handbook' => 'https://www.drupal.org/docs/8/upgrade/known-issues-when-upgrading-from-drupal-6-or-7-to-drupal-8#id_conflicts']) . '</p>';
 
-    sort($content_conflicts);
     $form['conflicts'] = [
       '#title' => $this->t('The conflicting content are of the following types:'),
       '#theme' => 'item_list',
-      '#items' => $content_conflicts,
+      '#items' => $this->formatConflicts($conflicts),
     ];
 
     return $form;
   }
 
   /**
+   * Formats a set of failing audit results as strings.
+   *
+   * Each string is the label of the destination plugin of the migration that
+   * failed the audit, keyed by the destination plugin ID in order to prevent
+   * duplication.
+   *
+   * @param \Drupal\migrate\Audit\AuditResult[] $conflicts
+   *   The failing audit results.
+   *
+   * @return string[]
+   *   The formatted audit results.
+   */
+  protected function formatConflicts(array $conflicts) {
+    $items = [];
+
+    foreach ($conflicts as $conflict) {
+      $definition = $conflict->getMigration()->getDestinationPlugin()->getPluginDefinition();
+      $id = $definition['id'];
+      $items[$id] = $definition['label'];
+    }
+    sort($items);
+
+    return $items;
+  }
+
+  /**
    * Build the markup for i18n warnings.
    *
    * @param array $form
    *   An associative array containing the structure of the form.
    * @param \Drupal\Core\Form\FormStateInterface $form_state
    *   The current state of the form.
-   * @param array $translated_content_conflicts
-   *   The conflicted translated migration labels.
+   * @param \Drupal\migrate\Audit\AuditResult[] $conflicts
+   *   The failing audit results.
    *
    * @return array
    *   The form structure.
    */
-  protected function i18nWarningForm(array &$form, FormStateInterface $form_state, $translated_content_conflicts) {
-    if (empty($translated_content_conflicts)) {
-      return $form;
-    }
-
+  protected function i18nWarningForm(array &$form, FormStateInterface $form_state, array $conflicts) {
     $form['warning']['#markup'] .= '<p>' . $this->t('It looks like you are migrating translated content. Be extra cautious and make sure you aren\'t introducting any conflicts. For more on the subject, see the online handbook entry for <a target="_blank" href=":id-conflicts-handbook">handling migration conflicts</a>.', [':id-conflicts-handbook' => 'https://www.drupal.org/docs/8/upgrade/known-issues-when-upgrading-from-drupal-6-or-7-to-drupal-8#id_conflicts']) . '</p>';
 
-    sort($translated_content_conflicts);
     $form['i18n'] = [
       '#title' => $this->t('The translated content are of the following types:'),
       '#theme' => 'item_list',
-      '#items' => $translated_content_conflicts,
+      '#items' => $this->formatConflicts($conflicts),
     ];
 
     return $form;