diff --git a/.github/workflows/build-2.x.yml b/.github/workflows/build-2.x.yml
index 27506495..6c78bcf9 100644
--- a/.github/workflows/build-2.x.yml
+++ b/.github/workflows/build-2.x.yml
@@ -23,12 +23,10 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # PHP 8.1 fails - see https://github.com/Islandora/islandora/issues/887
-        php-versions: ["7.4", "8.0", "8.1"]
+        php-versions: ["8.1"]
         # test-suite functional-javascript will appear to pass but will skip tests; missing chromedriver.
         test-suite: ["kernel", "functional", "functional-javascript"]
-        # Not yet Drupal 10 ready - see https://github.com/Islandora/islandora/issues/888
-        drupal-version: ["9.4.x", "9.5.x"]
+        drupal-version: ["9.5.x", "10.0.x", "10.1.x"]
         mysql: ["8.0"]
         allowed_failure: [false]
 
diff --git a/composer.json b/composer.json
index bf274cd1..7706ec74 100644
--- a/composer.json
+++ b/composer.json
@@ -14,10 +14,10 @@
     }
   ],
   "require": {
-    "drupal/context": "^4",
+    "drupal/context": "^4 || ^5@RC",
     "drupal/ctools": "^3.8 || ^4",
     "drupal/eva" : "^3.0",
-    "drupal/features" : "^3.7",
+    "drupal/features" : "^3.13",
     "drupal/file_replace": "^1.1",
     "drupal/filehash": "^2",
     "drupal/flysystem" : "^2.0@alpha",
@@ -29,7 +29,7 @@
     "drupal/token" : "^1.3",
     "islandora/chullo": "^2.0",
     "islandora/fedora-entity-mapper": "^1.0",
-    "islandora/jsonld": "^2",
+    "islandora/jsonld": "^2 || ^3",
     "stomp-php/stomp-php": "4.* || ^5"
   },
   "require-dev": {
diff --git a/islandora.info.yml b/islandora.info.yml
index 0336d89d..34e8118a 100644
--- a/islandora.info.yml
+++ b/islandora.info.yml
@@ -4,32 +4,31 @@ name: 'islandora'
 description: "Islandora Core"
 type: module
 package: Islandora
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
+  - context:context_ui
+  - ctools:ctools
+  - drupal:action
+  - drupal:basic_auth
   - drupal:block
+  - drupal:content_translation
+  - drupal:link
+  - drupal:media
   - drupal:node
-  - drupal:path
-  - drupal:text
   - drupal:options
-  - drupal:link
-  - jsonld:jsonld
-  - search_api:search_api
-  - jwt:jwt
+  - drupal:path
   - drupal:rest
-  - filehash:filehash
-  - drupal:basic_auth
-  - context:context_ui
-  - drupal:action
-  - eva:eva
   - drupal:taxonomy
+  - drupal:text
   - drupal:views_ui
-  - drupal:media
-  - prepopulate:prepopulate
+  - eva:eva
   - features:features_ui
-  - migrate_source_csv:migrate_source_csv
-  - drupal:content_translation
+  - file_replace:file_replace
+  - filehash:filehash
   - flysystem:flysystem
+  - jsonld:jsonld
+  - jwt:jwt
+  - migrate_source_csv:migrate_source_csv
+  - prepopulate:prepopulate
+  - search_api:search_api
   - token:token
-  - file_replace:file_replace
-  - ctools:ctools
diff --git a/modules/islandora_advanced_search/islandora_advanced_search.info.yml b/modules/islandora_advanced_search/islandora_advanced_search.info.yml
index 524e9dc7..19fae53a 100644
--- a/modules/islandora_advanced_search/islandora_advanced_search.info.yml
+++ b/modules/islandora_advanced_search/islandora_advanced_search.info.yml
@@ -4,7 +4,7 @@ name: 'Islandora Advanced Search'
 description: "Creates an Advanced Search block and other enhancements to search."
 type: module
 package: Islandora
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
   - drupal:facets
   - drupal:facets_summary
diff --git a/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php b/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
index c00ce566..09dd1646 100644
--- a/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
+++ b/modules/islandora_advanced_search/src/Form/AdvancedSearchForm.php
@@ -71,7 +71,7 @@ class AdvancedSearchForm extends FormBase {
    */
   public static function create(ContainerInterface $container) {
     return new static(
-      $container->get('request_stack')->getMasterRequest(),
+      $container->get('request_stack')->getMainRequest(),
       $container->get('current_route_match')
     );
   }
diff --git a/modules/islandora_advanced_search/src/Plugin/Block/AdvancedSearchBlock.php b/modules/islandora_advanced_search/src/Plugin/Block/AdvancedSearchBlock.php
index c5f5adb8..2aa77f12 100644
--- a/modules/islandora_advanced_search/src/Plugin/Block/AdvancedSearchBlock.php
+++ b/modules/islandora_advanced_search/src/Plugin/Block/AdvancedSearchBlock.php
@@ -108,7 +108,7 @@ class AdvancedSearchBlock extends BlockBase implements ContainerFactoryPluginInt
       $plugin_definition,
       $container->get('plugin.manager.search_api.display'),
       $container->get('form_builder'),
-      $container->get('request_stack')->getMasterRequest()
+      $container->get('request_stack')->getMainRequest()
     );
   }
 
diff --git a/modules/islandora_advanced_search/src/Plugin/Block/SearchResultsPagerBlock.php b/modules/islandora_advanced_search/src/Plugin/Block/SearchResultsPagerBlock.php
index f2e4a170..e1e477d8 100644
--- a/modules/islandora_advanced_search/src/Plugin/Block/SearchResultsPagerBlock.php
+++ b/modules/islandora_advanced_search/src/Plugin/Block/SearchResultsPagerBlock.php
@@ -58,7 +58,7 @@ class SearchResultsPagerBlock extends BlockBase implements ContainerFactoryPlugi
       $configuration,
       $plugin_id,
       $plugin_definition,
-      $container->get('request_stack')->getMasterRequest()
+      $container->get('request_stack')->getMainRequest()
     );
   }
 
diff --git a/modules/islandora_audio/islandora_audio.info.yml b/modules/islandora_audio/islandora_audio.info.yml
index 998590f5..5e6beb5a 100644
--- a/modules/islandora_audio/islandora_audio.info.yml
+++ b/modules/islandora_audio/islandora_audio.info.yml
@@ -2,7 +2,6 @@ name: 'Islandora Audio'
 description: 'Islandora audio derivative actions'
 type: module
 package: Islandora
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
   - drupal:islandora
diff --git a/modules/islandora_breadcrumbs/islandora_breadcrumbs.info.yml b/modules/islandora_breadcrumbs/islandora_breadcrumbs.info.yml
index c76020cb..661ec70a 100644
--- a/modules/islandora_breadcrumbs/islandora_breadcrumbs.info.yml
+++ b/modules/islandora_breadcrumbs/islandora_breadcrumbs.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora Breadcrumbs'
 type: module
 description: 'Builds breadcrumbs based on field_member_of relationships.'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Islandora
 dependencies:
   - islandora:islandora
diff --git a/modules/islandora_core_feature/islandora_core_feature.info.yml b/modules/islandora_core_feature/islandora_core_feature.info.yml
index bf4f8d7a..6976eb8c 100755
--- a/modules/islandora_core_feature/islandora_core_feature.info.yml
+++ b/modules/islandora_core_feature/islandora_core_feature.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora Core Feature'
 description: 'Minimum configuration required for Islandora.'
 type: module
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
   - drupal:basic_auth
   - drupal:content_translation
diff --git a/modules/islandora_iiif/islandora_iiif.info.yml b/modules/islandora_iiif/islandora_iiif.info.yml
index 0492158a..39b835c0 100644
--- a/modules/islandora_iiif/islandora_iiif.info.yml
+++ b/modules/islandora_iiif/islandora_iiif.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora IIIF'
 type: module
 description: 'IIIF support for Islandora'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Islandora
 dependencies:
   - drupal:islandora
diff --git a/modules/islandora_image/islandora_image.info.yml b/modules/islandora_image/islandora_image.info.yml
index 87076462..277966f3 100644
--- a/modules/islandora_image/islandora_image.info.yml
+++ b/modules/islandora_image/islandora_image.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora Image'
 type: module
 description: 'Islandora Image derivative actions'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Islandora
 dependencies:
   - drupal:islandora
diff --git a/modules/islandora_text_extraction/islandora_text_extraction.info.yml b/modules/islandora_text_extraction/islandora_text_extraction.info.yml
index 67687f90..fb768e2a 100644
--- a/modules/islandora_text_extraction/islandora_text_extraction.info.yml
+++ b/modules/islandora_text_extraction/islandora_text_extraction.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora Text Extraction'
 type: module
 description: 'Islandora 8 module to connect to Hypercube microservice, and to get text from PDF ingest'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: 'Islandora'
 dependencies:
   - drupal:islandora
diff --git a/modules/islandora_text_extraction_defaults/islandora_text_extraction_defaults.info.yml b/modules/islandora_text_extraction_defaults/islandora_text_extraction_defaults.info.yml
index 5b9aa14f..8596dbd3 100644
--- a/modules/islandora_text_extraction_defaults/islandora_text_extraction_defaults.info.yml
+++ b/modules/islandora_text_extraction_defaults/islandora_text_extraction_defaults.info.yml
@@ -1,8 +1,7 @@
 name: 'Islandora Text Extraction Defaults'
 type: module
 description: 'Default config for the Islandora Text Extraction module.'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Islandora
 dependencies:
   - drupal:field
diff --git a/modules/islandora_video/islandora_video.info.yml b/modules/islandora_video/islandora_video.info.yml
index 48eb82f2..aa51af11 100644
--- a/modules/islandora_video/islandora_video.info.yml
+++ b/modules/islandora_video/islandora_video.info.yml
@@ -2,7 +2,6 @@ name: 'Islandora Video'
 description: 'Islandora video derivative actions'
 type: module
 package: Islandora
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
   - drupal:islandora
diff --git a/src/EventGenerator/EventGenerator.php b/src/EventGenerator/EventGenerator.php
index 6b3a4c5c..b975f608 100644
--- a/src/EventGenerator/EventGenerator.php
+++ b/src/EventGenerator/EventGenerator.php
@@ -192,6 +192,7 @@ class EventGenerator implements EventGeneratorInterface {
   protected function getRevisionIds(Media $media, EntityStorageInterface $media_storage) {
     $result = $media_storage->getQuery()
       ->allRevisions()
+      ->accessCheck(TRUE)
       ->condition($media->getEntityType()->getKey('id'), $media->id())
       ->sort($media->getEntityType()->getKey('revision'), 'DESC')
       ->execute();
diff --git a/src/Flysystem/Adapter/FedoraAdapter.php b/src/Flysystem/Adapter/FedoraAdapter.php
index 55f8b11d..0871827e 100644
--- a/src/Flysystem/Adapter/FedoraAdapter.php
+++ b/src/Flysystem/Adapter/FedoraAdapter.php
@@ -3,7 +3,6 @@
 namespace Drupal\islandora\Flysystem\Adapter;
 
 use GuzzleHttp\Psr7\Header;
-use function GuzzleHttp\Psr7\parse_header;
 use Drupal\Core\Logger\LoggerChannelInterface;
 use Islandora\Chullo\IFedoraApi;
 use League\Flysystem\AdapterInterface;
@@ -160,14 +159,8 @@ class FedoraAdapter implements AdapterInterface {
     // NonRDFSource's are considered files.  Everything else is a
     // directory.
     $type = 'dir';
-    // phpcs:disable
-    if (class_exists(Header::class)) {
-      $links = Header::parse($response->getHeader('Link'));
-    }
-    else {
-      $links = parse_header($response->getHeader('Link'));
-    }
-    // phpcs:enable
+    $links = Header::parse($response->getHeader('Link'));
+
     foreach ($links as $link) {
       if ($link['rel'] == 'type' && $link[0] == '<http://www.w3.org/ns/ldp#NonRDFSource>') {
         $type = 'file';
@@ -403,14 +396,7 @@ class FedoraAdapter implements AdapterInterface {
     $return = NULL;
     if ($response->getStatusCode() == 410) {
       $return = FALSE;
-      // phpcs:disable
-      if (class_exists(Header::class)) {
-        $link_headers = Header::parse($response->getHeader('Link'));
-      }
-      else {
-        $link_headers = parse_header($response->getHeader('Link'));
-      }
-      // phpcs:enable
+      $link_headers = Header::parse($response->getHeader('Link'));
       if ($link_headers) {
         $tombstones = array_filter($link_headers, function ($o) {
           return (isset($o['rel']) && $o['rel'] == 'hasTombstone');
diff --git a/src/Form/ConfirmDeleteMediaAndFile.php b/src/Form/ConfirmDeleteMediaAndFile.php
index 64c1bff3..a9613871 100644
--- a/src/Form/ConfirmDeleteMediaAndFile.php
+++ b/src/Form/ConfirmDeleteMediaAndFile.php
@@ -128,6 +128,9 @@ class ConfirmDeleteMediaAndFile extends DeleteMultipleForm {
       // Check for files.
       $fields = $this->entityFieldManager->getFieldDefinitions('media', $entity->bundle());
       foreach ($fields as $field) {
+        if ($field->getName() == 'thumbnail') {
+          continue;
+        }
         $type = $field->getType();
         if ($type == 'file' || $type == 'image') {
           $target_id = $entity->get($field->getName())->target_id;
@@ -137,8 +140,11 @@ class ConfirmDeleteMediaAndFile extends DeleteMultipleForm {
               $inaccessible_entities[] = $file;
               continue;
             }
-            $delete_files[$file->id()] = $file;
-            $total_count++;
+            if (!array_key_exists($file->id(), $delete_files)) {
+              $delete_files[$file->id()] = $file;
+              $total_count++;
+            }
+
           }
         }
       }
diff --git a/src/Plugin/Condition/NodeReferencedByNode.php b/src/Plugin/Condition/NodeReferencedByNode.php
index c5611a3e..d6db01ea 100644
--- a/src/Plugin/Condition/NodeReferencedByNode.php
+++ b/src/Plugin/Condition/NodeReferencedByNode.php
@@ -128,6 +128,7 @@ class NodeReferencedByNode extends ConditionPluginBase implements ContainerFacto
     $config = FieldStorageConfig::loadByName('node', $reference_field);
     if ($config) {
       $id_count = \Drupal::entityQuery('node')
+        ->accessCheck(TRUE)
         ->condition($reference_field, $entity->id())
         ->count()
         ->execute();
diff --git a/tests/modules/integer_weight_test_views/integer_weight_test_views.info.yml b/tests/modules/integer_weight_test_views/integer_weight_test_views.info.yml
index 7e298142..77b12ec3 100644
--- a/tests/modules/integer_weight_test_views/integer_weight_test_views.info.yml
+++ b/tests/modules/integer_weight_test_views/integer_weight_test_views.info.yml
@@ -2,7 +2,7 @@ name: 'Integer weight test views'
 type: module
 description: 'Provides default views for integer weight views tests.'
 package: Testing
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^8 || ^9 || ^10
 dependencies:
   - drupal:node
   - drupal:views
diff --git a/tests/src/Functional/DeleteMediaTest.php b/tests/src/Functional/DeleteMediaTest.php
index 86895dbb..c52eca31 100644
--- a/tests/src/Functional/DeleteMediaTest.php
+++ b/tests/src/Functional/DeleteMediaTest.php
@@ -50,8 +50,15 @@ class DeleteMediaTest extends IslandoraFunctionalTestBase {
   public function setUp(): void {
     parent::setUp();
 
+    if (version_compare(\Drupal::VERSION, '10.1', '>=')) {
+      $permissions = ['create media', 'delete any media', 'delete any file'];
+    }
+    else {
+      $permissions = ['create media', 'delete any media'];
+    }
+
     // Create a test user.
-    $this->account = $this->createUser(['create media', 'delete any media']);
+    $this->account = $this->createUser($permissions);
 
     list($this->file, $this->media) = $this->makeMediaAndFile($this->account);
   }
diff --git a/tests/src/Kernel/FedoraAdapterTest.php b/tests/src/Kernel/FedoraAdapterTest.php
index d6adecbb..9067d369 100644
--- a/tests/src/Kernel/FedoraAdapterTest.php
+++ b/tests/src/Kernel/FedoraAdapterTest.php
@@ -4,7 +4,6 @@ namespace Drupal\Tests\islandora\Kernel;
 
 use Prophecy\PhpUnit\ProphecyTrait;
 use GuzzleHttp\Psr7\Utils;
-use function GuzzleHttp\Psr7\stream_for;
 use Drupal\Core\Logger\LoggerChannelInterface;
 use Drupal\islandora\Flysystem\Adapter\FedoraAdapter;
 use GuzzleHttp\Psr7\Response;
@@ -61,13 +60,8 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
       ]);
     $prophecy->getHeader('Content-Type')->willReturn(['text/plain']);
     $prophecy->getHeader('Content-Length')->willReturn([strlen("DERP")]);
-    // phpcs:disable
-    if (class_exists(Utils::class)) {
-      $prophecy->getBody()->willReturn(Utils::streamFor("DERP"));
-    } else {
-      $prophecy->getBody()->willReturn(stream_for("DERP"));
-    }
-    // phpcs:enable
+    $prophecy->getBody()->willReturn(Utils::streamFor("DERP"));
+
     return $prophecy;
   }
 
@@ -241,7 +235,7 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
     $head_prophecy = $this->prophesize(Response::class);
     $head_prophecy->getStatusCode()->willReturn(410);
     $head_prophecy->getHeader('Link')
-      ->willReturn('<some-path-to-a-tombstone>; rel="hasTombstone"');
+      ->willReturn(['<some-path-to-a-tombstone>; rel="hasTombstone"']);
 
     $tombstone_prophecy = $this->prophesize(Response::class);
     $tombstone_prophecy->getStatusCode()->willReturn(204);
@@ -269,7 +263,7 @@ class FedoraAdapterTest extends IslandoraKernelTestBase {
     $head_prophecy = $this->prophesize(Response::class);
     $head_prophecy->getStatusCode()->willReturn(410);
     $head_prophecy->getHeader('Link')
-      ->willReturn('<some-path-to-a-tombstone>; rel="hasTombstone"');
+      ->willReturn(['<some-path-to-a-tombstone>; rel="hasTombstone"']);
 
     $tombstone_prophecy = $this->prophesize(Response::class);
     $tombstone_prophecy->getStatusCode()->willReturn(500);
diff --git a/tests/src/Kernel/FedoraPluginTest.php b/tests/src/Kernel/FedoraPluginTest.php
index cd1c8325..92a8137c 100644
--- a/tests/src/Kernel/FedoraPluginTest.php
+++ b/tests/src/Kernel/FedoraPluginTest.php
@@ -6,6 +6,7 @@ use Drupal\Core\Logger\LoggerChannelInterface;
 use Drupal\islandora\Flysystem\Fedora;
 use Islandora\Chullo\IFedoraApi;
 use League\Flysystem\AdapterInterface;
+use Prophecy\PhpUnit\ProphecyTrait;
 use Psr\Http\Message\ResponseInterface;
 use Symfony\Component\Mime\MimeTypeGuesserInterface;
 
@@ -17,6 +18,8 @@ use Symfony\Component\Mime\MimeTypeGuesserInterface;
  */
 class FedoraPluginTest extends IslandoraKernelTestBase {
 
+  use ProphecyTrait;
+
   /**
    * Mocks up a plugin.
    */