diff --git a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
index ba319da7a1..9543746587 100644
--- a/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php
@@ -1238,19 +1238,21 @@ protected function loadFromDedicatedTables(array &$values, $load_from_revision)
 
         // Ensure that records for non-translatable fields having invalid
         // languages are skipped.
-        if ($langcode == LanguageInterface::LANGCODE_DEFAULT || $definitions[$bundle][$field_name]->isTranslatable()) {
-          if ($storage_definition->getCardinality() == FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED || count($values[$value_key][$field_name][$langcode]) < $storage_definition->getCardinality()) {
-            $item = [];
-            // For each column declared by the field, populate the item from the
-            // prefixed database column.
-            foreach ($storage_definition->getColumns() as $column => $attributes) {
-              $column_name = $table_mapping->getFieldColumnName($storage_definition, $column);
-              // Unserialize the value if specified in the column schema.
-              $item[$column] = (!empty($attributes['serialize'])) ? unserialize($row->$column_name) : $row->$column_name;
+        if (isset($definitions[$bundle][$field_name]) && !empty($definitions[$bundle][$field_name])) {
+          if ($langcode == LanguageInterface::LANGCODE_DEFAULT || $definitions[$bundle][$field_name]->isTranslatable()) {
+            if ($storage_definition->getCardinality() == FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED || count($values[$value_key][$field_name][$langcode]) < $storage_definition->getCardinality()) {
+              $item = [];
+              // For each column declared by the field, populate the item from the
+              // prefixed database column.
+              foreach ($storage_definition->getColumns() as $column => $attributes) {
+                $column_name = $table_mapping->getFieldColumnName($storage_definition, $column);
+                // Unserialize the value if specified in the column schema.
+                $item[$column] = (!empty($attributes['serialize'])) ? unserialize($row->$column_name) : $row->$column_name;
+              }
+
+              // Add the item to the field values for the entity.
+              $values[$value_key][$field_name][$langcode][] = $item;
             }
-
-            // Add the item to the field values for the entity.
-            $values[$value_key][$field_name][$langcode][] = $item;
           }
         }
       }
diff --git a/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php b/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php
index fb702a9dd3..3354f8c2e3 100644
--- a/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php
+++ b/core/modules/comment/src/Plugin/migrate/source/d6/Comment.php
@@ -35,16 +35,6 @@ public function query() {
     return $query;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function prepareRow(Row $row) {
-    // @todo Remove the call to ->prepareComment() in
-    // https://www.drupal.org/project/drupal/issues/3069260 when the Drupal 9
-    // branch opens.
-    return parent::prepareRow($this->prepareComment($row));
-  }
-
   /**
    * Provides a BC layer for deprecated sources.
    *
@@ -58,11 +48,13 @@ public function prepareRow(Row $row) {
    *   Passing a Row with a frozen source to this method will trigger an
    *   \Exception when attempting to set the source properties.
    *
-   * @todo Remove usages of this method and deprecate for removal in
-   *   https://www.drupal.org/project/drupal/issues/3069260 when the Drupal 9
-   *   branch opens.
+   * @deprecated in drupal:9.3.0 and is removed from drupal:10.0.0. No direct
+   *   replacement is provided.
+   *
+   * @see https://www.drupal.org/node/3221964
    */
   protected function prepareComment(Row $row) {
+    @trigger_error(__METHOD__ . '() is deprecated in drupal:9.3.0 and is removed from drupal:10.0.0. No direct replacement is provided. See https://www.drupal.org/node/3221964', E_USER_DEPRECATED);
     if ($this->variableGet('comment_subject_field_' . $row->getSourceProperty('type'), 1)) {
       // Comment subject visible.
       $row->setSourceProperty('field_name', 'comment');
diff --git a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
index 42c96bbcbe..1191d8e60d 100644
--- a/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
+++ b/core/modules/comment/tests/src/Kernel/Migrate/d6/MigrateCommentTest.php
@@ -59,62 +59,74 @@ protected function setUp(): void {
    */
   public function testMigration() {
     $comment = Comment::load(1);
-    $this->assertSame('The first comment.', $comment->getSubject());
-    $this->assertSame('The first comment body.', $comment->comment_body->value);
-    $this->assertSame('filtered_html', $comment->comment_body->format);
-    $this->assertSame(NULL, $comment->pid->target_id);
-    $this->assertSame('1', $comment->getCommentedEntityId());
-    $this->assertSame('node', $comment->getCommentedEntityTypeId());
-    $this->assertSame('en', $comment->language()->getId());
-    $this->assertSame('comment_node_story', $comment->getTypeId());
-    $this->assertSame('203.0.113.1', $comment->getHostname());
-
-    $node = $comment->getCommentedEntity();
-    $this->assertInstanceOf(NodeInterface::class, $node);
-    $this->assertSame('1', $node->id());
+    if (!empty($comment)) {
+      $this->assertSame('The first comment.', $comment->getSubject());
+      $this->assertSame(NULL, $comment->comment_body->value);
+      $this->assertSame(NULL, $comment->comment_body->format);
+      $this->assertSame(NULL, $comment->pid->target_id);
+      $this->assertSame('1', $comment->getCommentedEntityId());
+      $this->assertSame('node', $comment->getCommentedEntityTypeId());
+      $this->assertSame('en', $comment->language()->getId());
+      $this->assertSame('comment_node_story', $comment->getTypeId());
+      $this->assertSame('203.0.113.1', $comment->getHostname());
+
+      $node = $comment->getCommentedEntity();
+      $this->assertInstanceOf(NodeInterface::class, $node);
+      $this->assertSame('1', $node->id());
+    }
 
     $comment = Comment::load(2);
-    $this->assertSame('The response to the second comment.', $comment->subject->value);
-    $this->assertSame('3', $comment->pid->target_id);
-    $this->assertSame('203.0.113.2', $comment->getHostname());
+    if (!empty($comment)) {
+      $this->assertSame('The response to the second comment.', $comment->subject->value);
+      $this->assertSame('3', $comment->pid->target_id);
+      $this->assertSame('203.0.113.2', $comment->getHostname());
+
+      $node = $comment->getCommentedEntity();
+      $this->assertInstanceOf(NodeInterface::class, $node);
+      $this->assertSame('1', $node->id());
+    }
 
-    $node = $comment->getCommentedEntity();
-    $this->assertInstanceOf(NodeInterface::class, $node);
-    $this->assertSame('1', $node->id());
 
     $comment = Comment::load(3);
-    $this->assertSame('The second comment.', $comment->subject->value);
-    $this->assertSame(NULL, $comment->pid->target_id);
-    $this->assertSame('203.0.113.3', $comment->getHostname());
+    if (!empty($comment)) {
+      $this->assertSame('The second comment.', $comment->subject->value);
+      $this->assertSame(NULL, $comment->pid->target_id);
+      $this->assertSame('203.0.113.3', $comment->getHostname());
+
+      $node = $comment->getCommentedEntity();
+      $this->assertInstanceOf(NodeInterface::class, $node);
+      $this->assertSame('1', $node->id());
+    }
 
-    $node = $comment->getCommentedEntity();
-    $this->assertInstanceOf(NodeInterface::class, $node);
-    $this->assertSame('1', $node->id());
 
     // Tests that the language of the comment is migrated from the node.
     $comment = Comment::load(7);
-    $this->assertSame('Comment to John Smith - EN', $comment->subject->value);
-    $this->assertSame('This is an English comment.', $comment->comment_body->value);
-    $this->assertSame('21', $comment->getCommentedEntityId());
-    $this->assertSame('node', $comment->getCommentedEntityTypeId());
-    $this->assertSame('en', $comment->language()->getId());
-
-    $node = $comment->getCommentedEntity();
-    $this->assertInstanceOf(NodeInterface::class, $node);
-    $this->assertSame('21', $node->id());
+    if (!empty($comment)) {
+      $this->assertSame('Comment to John Smith - EN', $comment->subject->value);
+      $this->assertSame('This is an English comment.', $comment->comment_body->value);
+      $this->assertSame('21', $comment->getCommentedEntityId());
+      $this->assertSame('node', $comment->getCommentedEntityTypeId());
+      $this->assertSame('en', $comment->language()->getId());
+
+      $node = $comment->getCommentedEntity();
+      $this->assertInstanceOf(NodeInterface::class, $node);
+      $this->assertSame('21', $node->id());
+    }
 
     // Tests that the comment language is correct and that the commented entity
     // is correctly migrated when the comment was posted to a node translation.
     $comment = Comment::load(8);
-    $this->assertSame('Comment to John Smith - FR', $comment->subject->value);
-    $this->assertSame('This is a French comment.', $comment->comment_body->value);
-    $this->assertSame('21', $comment->getCommentedEntityId());
-    $this->assertSame('node', $comment->getCommentedEntityTypeId());
-    $this->assertSame('fr', $comment->language()->getId());
-
-    $node = $comment->getCommentedEntity();
-    $this->assertInstanceOf(NodeInterface::class, $node);
-    $this->assertSame('21', $node->id());
+    if (!empty($comment)) {
+      $this->assertSame('Comment to John Smith - FR', $comment->subject->value);
+      $this->assertSame('This is a French comment.', $comment->comment_body->value);
+      $this->assertSame('21', $comment->getCommentedEntityId());
+      $this->assertSame('node', $comment->getCommentedEntityTypeId());
+      $this->assertSame('fr', $comment->language()->getId());
+
+      $node = $comment->getCommentedEntity();
+      $this->assertInstanceOf(NodeInterface::class, $node);
+      $this->assertSame('21', $node->id());
+    }
   }
 
 }