diff --git a/replication.info.yml b/replication.info.yml
old mode 100644
new mode 100755
index 620ee31..a057d21
--- a/replication.info.yml
+++ b/replication.info.yml
@@ -2,7 +2,7 @@ name: 'Replication'
 type: module
 description: 'Provides services and entities types to assist with and log content replication.'
 version: VERSION
-core: 8.x
+core_version_requirement: ^8 || ^9
 configure: replication.settings_form
 dependencies:
-  - multiversion:multiversion
+  - multiversion:multiversion
\ No newline at end of file
diff --git a/replication.services.yml b/replication.services.yml
old mode 100644
new mode 100755
index b389271..0b64c41
--- a/replication.services.yml
+++ b/replication.services.yml
@@ -14,7 +14,7 @@ services:
 #Factories
   replication.changes_factory:
     class: Drupal\replication\ChangesFactory
-    arguments: ['@multiversion.entity_index.sequence', '@entity.manager', '@serializer', '@plugin.manager.replication_filter']
+    arguments: ['@multiversion.entity_index.sequence', '@entity_type.manager', '@serializer', '@plugin.manager.replication_filter']
   replication.revisiondiff_factory:
     class: Drupal\replication\RevisionDiffFactory
     arguments: ['@multiversion.entity_index.rev']
@@ -38,17 +38,17 @@ services:
 #Normalizers
   replication.normalizer.link_item:
     class: Drupal\replication\Normalizer\LinkItemNormalizer
-    arguments: ['@entity_type.manager', '@path.alias_manager', '@plugin.manager.entity_reference_selection']
+    arguments: ['@entity_type.manager', '@path_alias.manager', '@plugin.manager.entity_reference_selection']
     tags:
       - { name: normalizer, priority: 40 }
   replication.normalizer.redirect_source_item:
     class: Drupal\replication\Normalizer\RedirectSourceItemNormalizer
-    arguments: ['@entity_type.manager', '@path.alias_manager', '@plugin.manager.entity_reference_selection']
+    arguments: ['@entity_type.manager', '@path_alias.manager', '@plugin.manager.entity_reference_selection']
     tags:
       - { name: normalizer, priority: 40 }
   replication.normalizer.content_entity:
     class: Drupal\replication\Normalizer\ContentEntityNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 40 }
   replication.normalizer.replication_log:
@@ -62,7 +62,7 @@ services:
       - { name: normalizer, priority: 50 }
   replication.normalizer.all_docs:
     class: Drupal\replication\Normalizer\AllDocsNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.uuid']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.uuid']
     tags:
       - { name: normalizer, priority: 40 }
   replication.normalizer.changes:
@@ -73,7 +73,7 @@ services:
     class: Drupal\replication\Normalizer\WorkspaceNormalizer
     tags:
       - { name: normalizer, priority: 50 }
-    arguments: ['@entity.manager']
+    arguments: ['@entity_type.manager']
   replication.normalizer.deleted_flag_item_list:
     class: Drupal\replication\Normalizer\DeletedFlagItemListNormalizer
     tags:
@@ -89,32 +89,32 @@ services:
       - { name: normalizer, priority: 50 }
   replication.normalizer.attachment:
     class: Drupal\replication\Normalizer\AttachmentNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 50 }
   replication.normalizer.file_entity:
     class: Drupal\replication\Normalizer\FileEntityNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher', '@replication.process_file_attachment']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher', '@replication.process_file_attachment']
     tags:
       - { name: normalizer, priority: 60 }
   replication.normalizer.taxonomy_term:
     class: Drupal\replication\Normalizer\TaxonomyTermNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 60 }
   replication.normalizer.menu_link_content:
     class: Drupal\replication\Normalizer\MenuLinkContentNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 60 }
   replication.normalizer.crop:
     class: Drupal\replication\Normalizer\CropNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 60 }
   replication.normalizer.paragraph:
     class: Drupal\replication\Normalizer\ParagraphNormalizer
-    arguments: ['@entity.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
+    arguments: ['@entity_type.manager', '@multiversion.entity_index.factory', '@language_manager', '@replication.users_mapping', '@module_handler', '@plugin.manager.entity_reference_selection', '@event_dispatcher']
     tags:
       - { name: normalizer, priority: 60 }
   replication.normalizer.webform_entity_reference_item:
@@ -145,3 +145,7 @@ services:
     class: Drupal\replication\Normalizer\EntityReferenceQuantityItemNormalizer
     tags:
     - { name: normalizer, priority: 60 }
+  replication.normalizer.datetime:
+    class: Drupal\replication\Normalizer\DrupalDateTimeNormalizer
+    tags:
+      - { name: normalizer }
diff --git a/src/Entity/ReplicationSettings.php b/src/Entity/ReplicationSettings.php
old mode 100644
new mode 100755
index 4d4ff0f..2d8bd3b
--- a/src/Entity/ReplicationSettings.php
+++ b/src/Entity/ReplicationSettings.php
@@ -15,6 +15,10 @@ use Drupal\replication\Entity\ReplicationSettingsInterface;
  *   id = "replication_settings",
  *   label = @Translation("Replication settings"),
  *   config_prefix = "replication_settings",
+ *   config_export = {
+ *     "id",
+ *     "label"
+ *   },
  *   entity_keys = {
  *     "id" = "id",
  *     "label" = "label"
diff --git a/src/Normalizer/ContentEntityNormalizer.php b/src/Normalizer/ContentEntityNormalizer.php
old mode 100644
new mode 100755
index 4e9141d..7fe6dfe
--- a/src/Normalizer/ContentEntityNormalizer.php
+++ b/src/Normalizer/ContentEntityNormalizer.php
@@ -4,7 +4,8 @@ namespace Drupal\replication\Normalizer;
 
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Entity\ContentEntityInterface;
-use Drupal\Core\Entity\EntityManagerInterface;
+#use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Entity\EntityTypeManager;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
@@ -71,7 +72,7 @@ class ContentEntityNormalizer extends NormalizerBase implements DenormalizerInte
   private $moduleHandler;
 
   /**
-   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   * @param \Drupal\Core\Entity\EntityTypeManager $entity_manager
    * @param \Drupal\multiversion\Entity\Index\MultiversionIndexFactory $index_factory
    * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
    * @param \Drupal\replication\UsersMapping $users_mapping
@@ -79,7 +80,7 @@ class ContentEntityNormalizer extends NormalizerBase implements DenormalizerInte
    * @param \Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface $selection_manager
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    */
-  public function __construct(EntityManagerInterface $entity_manager, MultiversionIndexFactory $index_factory, LanguageManagerInterface $language_manager, UsersMapping $users_mapping, ModuleHandlerInterface $module_handler, SelectionPluginManagerInterface $selection_manager = NULL, EventDispatcherInterface $event_dispatcher = NULL) {
+  public function __construct(EntityTypeManager $entity_manager, MultiversionIndexFactory $index_factory, LanguageManagerInterface $language_manager, UsersMapping $users_mapping, ModuleHandlerInterface $module_handler, SelectionPluginManagerInterface $selection_manager = NULL, EventDispatcherInterface $event_dispatcher = NULL) {
     $this->entityManager = $entity_manager;
     $this->indexFactory = $index_factory;
     $this->languageManager = $language_manager;
@@ -247,7 +248,7 @@ class ContentEntityNormalizer extends NormalizerBase implements DenormalizerInte
     $translations = [];
     foreach ($data as $key => $translation) {
       // Skip any keys that start with '_' or '@'.
-      if (in_array($key{0}, ['_', '@'])) {
+      if (in_array($key[0], ['_', '@'])) {
         continue;
       }
       // When language is configured, undefined or not applicable go ahead with
diff --git a/src/Normalizer/EntityReferenceItemNormalizer.php b/src/Normalizer/EntityReferenceItemNormalizer.php
old mode 100644
new mode 100755
index 2543dfc..6dbb670
--- a/src/Normalizer/EntityReferenceItemNormalizer.php
+++ b/src/Normalizer/EntityReferenceItemNormalizer.php
@@ -49,7 +49,7 @@ class EntityReferenceItemNormalizer extends FieldItemNormalizer {
     ];
 
     // Add username to the field info for user entity type.
-    if ($target_type === 'user' && $username = $referenced_entity->getUsername()) {
+    if ($target_type === 'user' && $username = $referenced_entity->getAccountName()) {
       $field_info['username'] = $username;
     }
 
diff --git a/src/Normalizer/FileEntityNormalizer.php b/src/Normalizer/FileEntityNormalizer.php
old mode 100644
new mode 100755
index 439eff7..aefb956
--- a/src/Normalizer/FileEntityNormalizer.php
+++ b/src/Normalizer/FileEntityNormalizer.php
@@ -2,7 +2,8 @@
 
 namespace Drupal\replication\Normalizer;
 
-use Drupal\Core\Entity\EntityManagerInterface;
+#use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Entity\EntityTypeManager;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\LanguageManagerInterface;
@@ -31,7 +32,7 @@ class FileEntityNormalizer extends ContentEntityNormalizer implements Denormaliz
   protected $processFileAttachment;
 
   /**
-   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   * @param \Drupal\Core\Entity\EntityTypeManager $entity_manager
    * @param \Drupal\multiversion\Entity\Index\MultiversionIndexFactory $index_factory
    * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
    * @param \Drupal\replication\UsersMapping $users_mapping
@@ -40,7 +41,7 @@ class FileEntityNormalizer extends ContentEntityNormalizer implements Denormaliz
    * @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $event_dispatcher
    * @param \Drupal\replication\ProcessFileAttachment $process_file_attachment
    */
-  public function __construct(EntityManagerInterface $entity_manager, MultiversionIndexFactory $index_factory, LanguageManagerInterface $language_manager, UsersMapping $users_mapping, ModuleHandlerInterface $module_handler, SelectionPluginManagerInterface $selection_manager = NULL, EventDispatcherInterface $event_dispatcher = NULL, ProcessFileAttachment $process_file_attachment) {
+  public function __construct(EntityTypeManager $entity_manager, MultiversionIndexFactory $index_factory, LanguageManagerInterface $language_manager, UsersMapping $users_mapping, ModuleHandlerInterface $module_handler, SelectionPluginManagerInterface $selection_manager = NULL, EventDispatcherInterface $event_dispatcher = NULL, ProcessFileAttachment $process_file_attachment) {
     parent::__construct($entity_manager, $index_factory, $language_manager, $users_mapping, $module_handler, $selection_manager, $event_dispatcher);
     $this->processFileAttachment = $process_file_attachment;
   }
@@ -50,7 +51,7 @@ class FileEntityNormalizer extends ContentEntityNormalizer implements Denormaliz
    */
   public function normalize($data, $format = NULL, array $context = []) {
     $normalized = parent::normalize($data, $format, $context);
-    $file_system = \Drupal::service('file_system');
+    $file_system = \Drupal::service('stream_wrapper_manager');
     $uri = $data->getFileUri();
 
     if (empty($uri)) {
@@ -58,7 +59,7 @@ class FileEntityNormalizer extends ContentEntityNormalizer implements Denormaliz
     }
 
     if ($file_contents = @file_get_contents($uri)) {
-      if (in_array($file_system->uriScheme($uri), ['public', 'private']) == FALSE) {
+      if (in_array($file_system->getScheme($uri), ['public', 'private']) == FALSE) {
         $file_data = '';
       }
       else {
diff --git a/src/Normalizer/LinkItemNormalizer.php b/src/Normalizer/LinkItemNormalizer.php
old mode 100644
new mode 100755
index 61993ad..d54a620
--- a/src/Normalizer/LinkItemNormalizer.php
+++ b/src/Normalizer/LinkItemNormalizer.php
@@ -7,7 +7,8 @@ use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\Path\AliasManagerInterface;
+#use Drupal\Core\Path\AliasManagerInterface;
+use Drupal\path_alias\AliasManager;
 use Drupal\Core\Url;
 use Drupal\multiversion\Entity\WorkspaceInterface;
 use Drupal\serialization\Normalizer\FieldItemNormalizer;
@@ -32,16 +33,16 @@ class LinkItemNormalizer extends FieldItemNormalizer {
   private $selectionManager;
 
   /**
-   * @var \Drupal\Core\Path\AliasManagerInterface
+   * @var \Drupal\path_alias\AliasManager
    */
   private $aliasManager;
 
   /**
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
-   * @param \Drupal\Core\Path\AliasManagerInterface $alias_manager
+   * @param \Drupal\path_alias\AliasManager $alias_manager
    * @param \Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface|null $selection_manager
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, AliasManagerInterface $alias_manager, SelectionPluginManagerInterface $selection_manager = NULL) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, AliasManager $alias_manager, SelectionPluginManagerInterface $selection_manager = NULL) {
     $this->entityTypeManager = $entity_type_manager;
     $this->selectionManager = $selection_manager;
     $this->aliasManager = $alias_manager;
diff --git a/src/Normalizer/RedirectSourceItemNormalizer.php b/src/Normalizer/RedirectSourceItemNormalizer.php
old mode 100644
new mode 100755
index 14e51bc..955a13f
--- a/src/Normalizer/RedirectSourceItemNormalizer.php
+++ b/src/Normalizer/RedirectSourceItemNormalizer.php
@@ -7,7 +7,8 @@ use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
-use Drupal\Core\Path\AliasManagerInterface;
+#use Drupal\Core\Path\AliasManagerInterface;
+use Drupal\path_alias\AliasManager;
 use Drupal\Core\Url;
 use Drupal\multiversion\Entity\WorkspaceInterface;
 use Drupal\serialization\Normalizer\FieldItemNormalizer;
@@ -32,16 +33,16 @@ class RedirectSourceItemNormalizer extends FieldItemNormalizer {
   private $selectionManager;
 
   /**
-   * @var \Drupal\Core\Path\AliasManagerInterface
+   * @var \Drupal\path_alias\AliasManager
    */
   private $aliasManager;
 
   /**
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
-   * @param \Drupal\Core\Path\AliasManagerInterface $alias_manager
+   * @param \Drupal\path_alias\AliasManager $alias_manager
    * @param \Drupal\Core\Entity\EntityReferenceSelection\SelectionPluginManagerInterface|null $selection_manager
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, AliasManagerInterface $alias_manager, SelectionPluginManagerInterface $selection_manager = NULL) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, AliasManager $alias_manager, SelectionPluginManagerInterface $selection_manager = NULL) {
     $this->entityTypeManager = $entity_type_manager;
     $this->selectionManager = $selection_manager;
     $this->aliasManager = $alias_manager;
diff --git a/src/Normalizer/WorkspaceNormalizer.php b/src/Normalizer/WorkspaceNormalizer.php
old mode 100644
new mode 100755
index c46b935..d04af87
--- a/src/Normalizer/WorkspaceNormalizer.php
+++ b/src/Normalizer/WorkspaceNormalizer.php
@@ -5,11 +5,16 @@ namespace Drupal\replication\Normalizer;
 use Drupal\multiversion\Entity\WorkspaceType;
 use Drupal\multiversion\Entity\WorkspaceTypeInterface;
 use Drupal\serialization\Normalizer\EntityNormalizer;
+use Drupal\Core\Entity\EntityTypeManager;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\serialization\Normalizer\NormalizerBase;
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 
 /**
  * @todo {@link https://www.drupal.org/node/2599920 Don't extend EntityNormalizer.}
  */
-class WorkspaceNormalizer extends EntityNormalizer {
+class WorkspaceNormalizer extends NormalizerBase implements DenormalizerInterface {
 
   /**
    * @var string[]
@@ -21,12 +26,20 @@ class WorkspaceNormalizer extends EntityNormalizer {
    */
   protected $format = ['json'];
 
+  /**
+   * @param \Drupal\Core\Entity\EntityTypeManager $entity_manager
+   */
+  public function __construct(EntityTypeManager $entity_manager) {
+    $this->entityManager = $entity_manager;
+  }
+
   /**
    * {@inheritdoc}
    */
   public function normalize($entity, $format = NULL, array $context = []) {
     $context['entity_type'] = 'workspace';
-    $data = parent::normalize($entity, $format, $context);
+    //$data = parent::normalize($entity, $format, $context);
+    $data = [];
 
     $return_data = [];
     if (isset($data['machine_name'])) {
diff --git a/src/ProcessFileAttachment.php b/src/ProcessFileAttachment.php
old mode 100644
new mode 100755
index 550fefc..19a90a5
--- a/src/ProcessFileAttachment.php
+++ b/src/ProcessFileAttachment.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\replication;
 
+use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Session\AccountProxyInterface;
 use Drupal\file\FileInterface;
@@ -71,7 +72,7 @@ class ProcessFileAttachment {
       ->getStorage('file')
       ->loadByProperties(['uri' => $uri]);
     if (count($existing_files)) {
-      $uri = file_destination($uri, FILE_EXISTS_RENAME);
+      $uri = file_destination($uri, FileSystemInterface::EXISTS_RENAME);
     }
     $file_context = [
       'uri' => $uri,
diff --git a/tests/modules/replication_alter_test/replication_alter_test.info.yml b/tests/modules/replication_alter_test/replication_alter_test.info.yml
old mode 100644
new mode 100755
index 21edd40..b76de04
--- a/tests/modules/replication_alter_test/replication_alter_test.info.yml
+++ b/tests/modules/replication_alter_test/replication_alter_test.info.yml
@@ -1,6 +1,6 @@
-name: 'Replication Alter Test'
+name: 'Replication alter test'
 type: module
-description: 'Tests content normalization alter events in replication.'
-core: 8.x
+description: 'Tests content normalization alter events in replication'
+core_version_requirement: ^8 || ^9
 version: VERSION
-hidden: true
+hidden: true
\ No newline at end of file
diff --git a/tests/src/Kernel/Normalizer/BulkDocsNormalizerTest.php b/tests/src/Kernel/Normalizer/BulkDocsNormalizerTest.php
old mode 100644
new mode 100755
index c043a56..491c3cf
--- a/tests/src/Kernel/Normalizer/BulkDocsNormalizerTest.php
+++ b/tests/src/Kernel/Normalizer/BulkDocsNormalizerTest.php
@@ -104,7 +104,7 @@ class BulkDocsNormalizerTest extends NormalizerTestBase {
 
   protected function createTestEntities($entity_type, $number = 3) {
     $entities = [];
-    $entity_manager = \Drupal::entityManager();
+    $entity_manager = \Drupal::entityTypeManager();
 
     while ($number >= 1) {
       $values = [