diff --git a/application/Espo/Core/Application.php b/application/Espo/Core/Application.php
index 259a00eca6..5e1522b242 100644
--- a/application/Espo/Core/Application.php
+++ b/application/Espo/Core/Application.php
@@ -104,21 +104,15 @@ class Application
     }
 
     /**
-     * Whether an application is installed.
+     * Whether the application is installed.
      */
     public function isInstalled(): bool
     {
-        $config = $this->getConfig();
-
-        if (file_exists($config->getConfigPath()) && $config->get('isInstalled')) {
-            return true;
-        }
-
-        return false;
+        return $this->getConfig()->get('isInstalled');
     }
 
     /**
-     * Get a service container.
+     * Get the service container.
      */
     public function getContainer(): Container
     {
diff --git a/application/Espo/Core/ApplicationRunners/Client.php b/application/Espo/Core/ApplicationRunners/Client.php
index 7af3e8cbd3..921f1c9367 100644
--- a/application/Espo/Core/ApplicationRunners/Client.php
+++ b/application/Espo/Core/ApplicationRunners/Client.php
@@ -32,6 +32,7 @@ namespace Espo\Core\ApplicationRunners;
 use Espo\Core\{
     Application\Runner,
     Utils\ClientManager,
+    Utils\Config,
 };
 
 /**
@@ -41,13 +42,22 @@ class Client implements Runner
 {
     private $clientManager;
 
-    public function __construct(ClientManager $clientManager)
+    private $config;
+
+    public function __construct(ClientManager $clientManager, Config $config)
     {
         $this->clientManager = $clientManager;
+        $this->config = $config;
     }
 
     public function run(): void
     {
+        if (!$this->config->get('isInstalled')) {
+            header("Location: install/");
+
+            return;
+        }
+
         $this->clientManager->display();
     }
 }
diff --git a/application/Espo/Core/Container/ContainerBuilder.php b/application/Espo/Core/Container/ContainerBuilder.php
index aa4a62336d..cdb8b1b1dc 100644
--- a/application/Espo/Core/Container/ContainerBuilder.php
+++ b/application/Espo/Core/Container/ContainerBuilder.php
@@ -163,7 +163,10 @@ class ContainerBuilder
         $bindingContainer = new BindingContainer($bindingLoader->load());
 
         return new $this->containerClassName(
-            $this->containerConfigurationClassName, $this->loaderClassNames, $this->services, $bindingContainer
+            $this->containerConfigurationClassName,
+            $this->loaderClassNames,
+            $this->services,
+            $bindingContainer
         );
     }
 }
diff --git a/application/Espo/Core/Portal/ApplicationRunners/Client.php b/application/Espo/Core/Portal/ApplicationRunners/Client.php
index fc5f5df814..7a4c0a41bc 100644
--- a/application/Espo/Core/Portal/ApplicationRunners/Client.php
+++ b/application/Espo/Core/Portal/ApplicationRunners/Client.php
@@ -52,7 +52,7 @@ class Client implements Runner
 
     public function run(): void
     {
-        $portalId = $this->applicationState->getPortal()->id;
+        $portalId = $this->applicationState->getPortal()->getId();
 
         $this->clientManager->display(null, null, [
             'portalId' => $portalId,
diff --git a/application/Espo/Core/Portal/Utils/Url.php b/application/Espo/Core/Portal/Utils/Url.php
index 7724ab3c81..f20fbe3e4a 100644
--- a/application/Espo/Core/Portal/Utils/Url.php
+++ b/application/Espo/Core/Portal/Utils/Url.php
@@ -33,9 +33,11 @@ class Url
 {
     public static function detectPortalIdForApi(): ?string
     {
-        if (!empty($_GET['portalId'])) {
-            return $_GET['portalId'];
-        }
+        $portalId = filter_input(INPUT_GET, 'portalId');
+
+        if ($portalId)  {
+            return $portalId;
+       }
 
         $url = $_SERVER['REQUEST_URI'];
 
@@ -90,9 +92,7 @@ class Url
             return false;
         }
 
-        $url = $_SERVER['REQUEST_URI'];
-
-        $a = explode('?', $url);
+        $a = explode('?', $_SERVER['REQUEST_URI']);
 
         $url = rtrim($a[0], '/');
 
diff --git a/application/Espo/Core/Utils/Config.php b/application/Espo/Core/Utils/Config.php
index 43338cf992..cab66c3405 100644
--- a/application/Espo/Core/Utils/Config.php
+++ b/application/Espo/Core/Utils/Config.php
@@ -34,7 +34,7 @@ use Espo\Core\{
     Utils\Config\ConfigFileManager,
 };
 
-use StdClass;
+use stdClass;
 use E_USER_DEPRECATED;
 
 /**
@@ -91,16 +91,22 @@ class Config
 
         $lastBranch = $this->loadConfig();
 
-        foreach ($keys as $keyName) {
-            if (isset($lastBranch[$keyName]) && (is_array($lastBranch) || is_object($lastBranch))) {
-                if (is_array($lastBranch)) {
-                    $lastBranch = $lastBranch[$keyName];
-                } else {
-                    $lastBranch = $lastBranch->$keyName;
-                }
-            } else {
+        foreach ($keys as $key) {
+            if (!is_array($lastBranch) && !is_object($lastBranch)) {
                 return $default;
             }
+
+            if (!isset($lastBranch[$key])) {
+                return $default;
+            }
+
+            if (is_array($lastBranch)) {
+                $lastBranch = $lastBranch[$key];
+
+                continue;
+            }
+
+            $lastBranch = $lastBranch->$key;
         }
 
         return $lastBranch;
@@ -115,16 +121,22 @@ class Config
 
         $lastBranch = $this->loadConfig();
 
-        foreach ($keys as $keyName) {
-            if (isset($lastBranch[$keyName]) && (is_array($lastBranch) || is_object($lastBranch))) {
-                if (is_array($lastBranch)) {
-                    $lastBranch = $lastBranch[$keyName];
-                } else {
-                    $lastBranch = $lastBranch->$keyName;
-                }
-            } else {
+        foreach ($keys as $key) {
+            if (!is_array($lastBranch) && !is_object($lastBranch)) {
                 return false;
             }
+
+            if (!isset($lastBranch[$key])) {
+                return false;
+            }
+
+            if (is_array($lastBranch)) {
+                $lastBranch = $lastBranch[$key];
+
+                continue;
+            }
+
+            $lastBranch = $lastBranch->$key;
         }
 
         return true;
@@ -269,8 +281,8 @@ class Config
         }
 
         $configPath = $this->fileManager->isFile($this->configPath) ?
-                $this->configPath :
-                $this->defaultConfigPath;
+            $this->configPath :
+            $this->defaultConfigPath;
 
         $this->data = $this->fileManager->getPhpContents($configPath);
 
@@ -286,7 +298,7 @@ class Config
     /**
      * Get all parameters.
      */
-    public function getAllData(): StdClass
+    public function getAllData(): stdClass
     {
         return (object) $this->loadConfig();
     }
diff --git a/index.php b/index.php
index 0843edc0b7..8bea931e04 100644
--- a/index.php
+++ b/index.php
@@ -37,13 +37,7 @@ use Espo\Core\{
 
 $app = new Application();
 
-if (!$app->isInstalled()) {
-    header("Location: install/");
-
-    exit;
-}
-
-if (!empty($_GET['entryPoint'])) {
+if (filter_has_var(INPUT_GET, 'entryPoint')) {
     $app->run(EntryPoint::class);
 
     exit;
diff --git a/portal/index.php b/portal/index.php
index 004de2edc7..7a5ae89298 100644
--- a/portal/index.php
+++ b/portal/index.php
@@ -53,14 +53,12 @@ if (Url::detectIsInPortalDir()) {
     $app->setClientBasePath($basePath);
 }
 
-if (!empty($_GET['entryPoint'])) {
+if (filter_has_var(INPUT_GET, 'entryPoint')) {
     $app->run(EntryPoint::class);
 
     exit;
 }
 
-$params = RunnerParams::fromArray([
-    'basePath' => $basePath,
-]);
+$params = RunnerParams::create()->with('basePath', $basePath);
 
 $app->run(PortalClient::class, $params);