diff --git a/application/Espo/Core/Authentication/AuthToken/EspoManager.php b/application/Espo/Core/Authentication/AuthToken/EspoManager.php
index 063a5fed34..c2621ad505 100644
--- a/application/Espo/Core/Authentication/AuthToken/EspoManager.php
+++ b/application/Espo/Core/Authentication/AuthToken/EspoManager.php
@@ -30,17 +30,16 @@
 namespace Espo\Core\Authentication\AuthToken;
 
 use Espo\ORM\EntityManager;
+use Espo\ORM\Repository\RDBRepository;
 use Espo\Entities\AuthToken as AuthTokenEntity;
 
 use RuntimeException;
 
-use const MCRYPT_DEV_URANDOM;
-
 class EspoManager implements Manager
 {
-    private $entityManager;
+    private EntityManager $entityManager;
 
-    private $repository;
+    private RDBRepository $repository;
 
     private const TOKEN_RANDOM_LENGTH = 16;
 
@@ -163,10 +162,6 @@ class EspoManager implements Manager
             return bin2hex(random_bytes($length));
         }
 
-        if (function_exists('mcrypt_create_iv')) {
-            return bin2hex(mcrypt_create_iv($length, MCRYPT_DEV_URANDOM));
-        }
-
         if (function_exists('openssl_random_pseudo_bytes')) {
             return bin2hex(openssl_random_pseudo_bytes($length));
         }
diff --git a/application/Espo/Core/FileStorage/Manager.php b/application/Espo/Core/FileStorage/Manager.php
index 87b7f64037..fa1fc3e7ed 100644
--- a/application/Espo/Core/FileStorage/Manager.php
+++ b/application/Espo/Core/FileStorage/Manager.php
@@ -51,6 +51,7 @@ class Manager
 
     /**
      * @var array<string,resource>
+     * @phpstan-ignore-next-line Used to prevent deleting from memory.
      */
     private $resourceMap = [];
 
diff --git a/application/Espo/Core/Utils/Crypt.php b/application/Espo/Core/Utils/Crypt.php
index 3848ef0df8..97f1e2159b 100644
--- a/application/Espo/Core/Utils/Crypt.php
+++ b/application/Espo/Core/Utils/Crypt.php
@@ -33,11 +33,11 @@ use RuntimeException;
 
 class Crypt
 {
-    private $key = null;
+    private string $cryptKey;
 
-    private $cryptKey = null;
+    private ?string $key = null;
 
-    private $iv = null;
+    private ?string $iv = null;
 
     public function __construct(Config $config)
     {
@@ -51,7 +51,7 @@ class Crypt
         }
 
         if (!$this->key) {
-            throw new RuntimeException("Could not hash key.");
+            throw new RuntimeException("Could not hash the key.");
         }
 
         return $this->key;
@@ -60,12 +60,11 @@ class Crypt
     private function getIv(): string
     {
         if ($this->iv === null) {
-            if (extension_loaded('openssl')) {
-                $this->iv = openssl_random_pseudo_bytes(16);
-            }
-            else {
-                $this->iv = mcrypt_create_iv(16, MCRYPT_RAND);
+            if (!extension_loaded('openssl')) {
+                throw new RuntimeException("openssl extension is not loaded.");
             }
+
+            $this->iv = openssl_random_pseudo_bytes(16);
         }
 
         return $this->iv;
@@ -75,44 +74,28 @@ class Crypt
     {
         $iv = $this->getIv();
 
-        if (extension_loaded('openssl')) {
-            return base64_encode(
-                openssl_encrypt($string, 'aes-256-cbc', $this->getKey(), OPENSSL_RAW_DATA , $iv) . $iv
-            );
+        if (!extension_loaded('openssl')) {
+            throw new RuntimeException("openssl extension is not loaded.");
         }
 
-        $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, 'cbc');
-
-        $pad = $block - (strlen($string) % $block);
-
-        $string .= str_repeat(chr($pad), $pad);
-
         return base64_encode(
-            mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $this->getKey(), $string, MCRYPT_MODE_CBC, $iv) . $iv
+            openssl_encrypt($string, 'aes-256-cbc', $this->getKey(), OPENSSL_RAW_DATA, $iv) . $iv
         );
     }
 
     public function decrypt(string $encryptedString): string
     {
         $encryptedStringDecoded = base64_decode($encryptedString);
-
         $string = substr($encryptedStringDecoded, 0, strlen($encryptedStringDecoded) - 16);
-
         $iv = substr($encryptedStringDecoded, -16);
 
-        if (extension_loaded('openssl')) {
-            return trim(
-                openssl_decrypt($string, 'aes-256-cbc', $this->getKey(), OPENSSL_RAW_DATA, $iv)
-            );
+        if (!extension_loaded('openssl')) {
+            throw new RuntimeException("openssl extension is not loaded.");
         }
 
-        $string = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $this->getKey(), $string, MCRYPT_MODE_CBC, $iv);
-
-        $len = strlen($string);
-
-        $pad = ord($string[$len - 1]);
-
-        return substr($string, 0, strlen($string) - $pad);
+        return trim(
+            openssl_decrypt($string, 'aes-256-cbc', $this->getKey(), OPENSSL_RAW_DATA, $iv)
+        );
     }
 
     public function generateKey(): string
diff --git a/application/Espo/ORM/SthCollection.php b/application/Espo/ORM/SthCollection.php
index e841cbf994..b3c485d681 100644
--- a/application/Espo/ORM/SthCollection.php
+++ b/application/Espo/ORM/SthCollection.php
@@ -62,11 +62,6 @@ class SthCollection implements Collection, IteratorAggregate, Countable
 
     private ?string $sql = null;
 
-    /**
-     * @var Entity[]
-     */
-    private array $entityList = [];
-
     private function __construct(EntityManager $entityManager)
     {
         $this->entityManager = $entityManager;
@@ -126,8 +121,6 @@ class SthCollection implements Collection, IteratorAggregate, Countable
 
                 $this->prepareEntity($entity);
 
-                $this->entityList[] = $entity;
-
                 yield $entity;
             }
         })();
diff --git a/application/Espo/Services/App.php b/application/Espo/Services/App.php
index 1440e90851..ad0c13430a 100644
--- a/application/Espo/Services/App.php
+++ b/application/Espo/Services/App.php
@@ -37,8 +37,6 @@ use Espo\Core\ORM\Entity as CoreEntity;
 
 use Espo\Core\{
     Acl,
-    AclManager,
-    Select\SelectBuilderFactory,
     DataManager,
     InjectableFactory,
     Utils\Metadata,
@@ -72,12 +70,8 @@ class App
 
     private $acl;
 
-    private $aclManager;
-
     private $dataManager;
 
-    private $selectBuilderFactory;
-
     private $injectableFactory;
 
     private $settingsService;
@@ -95,9 +89,7 @@ class App
         EntityManager $entityManager,
         Metadata $metadata,
         Acl $acl,
-        AclManager $aclManager,
         DataManager $dataManager,
-        SelectBuilderFactory $selectBuilderFactory,
         InjectableFactory $injectableFactory,
         SettingsService $settingsService,
         User $user,
@@ -109,9 +101,7 @@ class App
         $this->entityManager = $entityManager;
         $this->metadata = $metadata;
         $this->acl = $acl;
-        $this->aclManager = $aclManager;
         $this->dataManager = $dataManager;
-        $this->selectBuilderFactory = $selectBuilderFactory;
         $this->injectableFactory = $injectableFactory;
         $this->settingsService = $settingsService;
         $this->user = $user;