diff --git a/src/Backend.php b/src/Backend.php
index 234b852..f66e321 100644
--- a/src/Backend.php
+++ b/src/Backend.php
@@ -14,7 +14,6 @@ declare(strict_types=1);
 
 namespace Dotclear\Plugin\myUrlHandlers;
 
-use dcAuth;
 use dcAdmin;
 use dcCore;
 use dcFavorites;
@@ -32,25 +31,30 @@ class Backend extends dcNsProcess
 
     public static function process(): bool
     {
-        if (!static::$init) {
+        if (!static::$init || is_null(dcCore::app()->auth) || is_null(dcCore::app()->blog) || is_null(dcCore::app()->adminurl)) {
             return false;
         }
 
+        // add backend sidebar menu icon
         dcCore::app()->menu[dcAdmin::MENU_PLUGINS]->addItem(
             My::name(),
             dcCore::app()->adminurl->get('admin.plugin.' . My::id()),
             dcPage::getPF(My::id() . '/icon.png'),
             preg_match('/' . preg_quote(dcCore::app()->adminurl->get('admin.plugin.' . My::id())) . '(&.*)?$/', $_SERVER['REQUEST_URI']),
-            dcCore::app()->auth->check(dcCore::app()->auth->makePermissions([dcAuth::PERMISSION_CONTENT_ADMIN]), dcCore::app()->blog->id)
+            dcCore::app()->auth->check(dcCore::app()->auth->makePermissions([dcCore::app()->auth::PERMISSION_CONTENT_ADMIN]), dcCore::app()->blog->id)
         );
 
+        // register user backend dashboard icon
         dcCore::app()->addBehavior('adminDashboardFavoritesV2', function (dcFavorites $favs): void {
+            if (is_null(dcCore::app()->auth) || is_null(dcCore::app()->adminurl)) {
+                return;
+            }
             $favs->register(My::id(), [
                 'title'       => My::name(),
                 'url'         => dcCore::app()->adminurl->get('admin.plugin.' . My::id()),
                 'small-icon'  => dcPage::getPF(My::id() . '/icon.png'),
                 'large-icon'  => dcPage::getPF(My::id() . '/icon-big.png'),
-                'permissions' => dcCore::app()->auth->makePermissions([dcAuth::PERMISSION_CONTENT_ADMIN]),
+                'permissions' => dcCore::app()->auth->makePermissions([dcCore::app()->auth::PERMISSION_CONTENT_ADMIN]),
             ]);
         });
 
diff --git a/src/Install.php b/src/Install.php
index 1932b08..a51fa57 100644
--- a/src/Install.php
+++ b/src/Install.php
@@ -22,14 +22,15 @@ class Install extends dcNsProcess
 {
     public static function init(): bool
     {
-        static::$init = defined('DC_CONTEXT_ADMIN') && dcCore::app()->newVersion(My::id(), dcCore::app()->plugins->moduleInfo(My::id(), 'version'));
+        static::$init = defined('DC_CONTEXT_ADMIN')
+            && dcCore::app()->newVersion(My::id(), dcCore::app()->plugins->moduleInfo(My::id(), 'version'));
 
         return static::$init;
     }
 
     public static function process(): bool
     {
-        if (!static::$init) {
+        if (!static::$init || is_null(dcCore::app()->blog)) {
             return false;
         }
 
@@ -58,14 +59,14 @@ class Install extends dcNsProcess
             );
 
             while ($record->fetch()) {
-                $value              = @unserialize($record->f('setting_value'));
-                $cur                = dcCore::app()->con->openCursor(dcCore::app()->prefix . dcNamespace::NS_TABLE_NAME);
-                $cur->setting_id    = My::NS_SETTING_ID;
-                $cur->setting_ns    = My::id();
-                $cur->setting_value = json_encode(is_array($value) ? $value : []);
+                $value = @unserialize($record->f('setting_value'));
+                $cur   = dcCore::app()->con->openCursor(dcCore::app()->prefix . dcNamespace::NS_TABLE_NAME);
+                $cur->setField('setting_id', My::NS_SETTING_ID);
+                $cur->setField('setting_ns', My::id());
+                $cur->setField('setting_value', json_encode(is_array($value) ? $value : []));
                 $cur->update(
                     "WHERE setting_id = '" . $record->f('setting_id') . "' and setting_ns = '" . $record->f('setting_ns') . "' " .
-                    'AND blog_id ' . (null === $record->f('blog_id') ? 'IS NULL ' : ("= '" . dcCore::app()->con->escape($record->f('blog_id')) . "' "))
+                    'AND blog_id ' . (null === $record->f('blog_id') ? 'IS NULL ' : ("= '" . dcCore::app()->con->escapeStr((string) $record->f('blog_id')) . "' "))
                 );
             }
         }
diff --git a/src/Manage.php b/src/Manage.php
index 13f1871..a2476d2 100644
--- a/src/Manage.php
+++ b/src/Manage.php
@@ -14,7 +14,6 @@ declare(strict_types=1);
 
 namespace Dotclear\Plugin\myUrlHandlers;
 
-use dcAuth;
 use dcCore;
 use dcNsProcess;
 use dcPage;
@@ -31,19 +30,17 @@ class Manage extends dcNsProcess
     public static function init(): bool
     {
         static::$init = defined('DC_CONTEXT_ADMIN')
-            && dcCore::app()->auth->check(
-                dcCore::app()->auth->makePermissions([
-                    dcAuth::PERMISSION_CONTENT_ADMIN,
-                ]),
-                dcCore::app()->blog->id
-            );
+            && !is_null(dcCore::app()->auth) && !is_null(dcCore::app()->blog)
+            && dcCore::app()->auth->check(dcCore::app()->auth->makePermissions([
+                dcCore::app()->auth::PERMISSION_CONTENT_ADMIN,
+            ]), dcCore::app()->blog->id);
 
         return static::$init;
     }
 
     public static function process(): bool
     {
-        if (!static::$init) {
+        if (!static::$init || is_null(dcCore::app()->adminurl)) {
             return false;
         }
 
@@ -117,7 +114,7 @@ class Manage extends dcNsProcess
 
     public static function render(): void
     {
-        if (!static::$init) {
+        if (!static::$init || is_null(dcCore::app()->blog)) {
             return;
         }
 
diff --git a/src/MyUrlHandlers.php b/src/MyUrlHandlers.php
index d786e07..547ce9f 100644
--- a/src/MyUrlHandlers.php
+++ b/src/MyUrlHandlers.php
@@ -18,10 +18,18 @@ use dcCore;
 
 class MyUrlHandlers
 {
-    private static $defaults     = [];
-    private static $url2post     = [];
-    private static $post_adm_url = [];
+    /** @var    array   $defaults   The default URLs handlers */
+    private static array $defaults = [];
 
+    /** @var    array   $url2post   The posts types URLs */
+    private static array $url2post = [];
+
+    /** @var    array   $post_adm_url   The posts types admin URLs */
+    private static array $post_adm_url = [];
+
+    /**
+     * Initialize handlers list.
+     */
     public static function init(): void
     {
         # Set defaults
@@ -50,6 +58,12 @@ class MyUrlHandlers
         }
     }
 
+    /**
+     * Override handler.
+     *
+     * @param   string  $name   The handler name
+     * @param   string  $url    The new url
+     */
     public static function overrideHandler(string $name, string $url): void
     {
         if (!isset(self::$defaults[$name])) {
@@ -70,6 +84,11 @@ class MyUrlHandlers
         }
     }
 
+    /**
+     * Get default URLs handlers
+     *
+     * @return  array   The default URLs handlers
+     */
     public static function getDefaults(): array
     {
         $res = [];
@@ -80,15 +99,31 @@ class MyUrlHandlers
         return $res;
     }
 
+    /**
+     * Get custom blog URLs handlers.
+     *
+     * @return  array   The blog URLs handlers
+     */
     public static function getBlogHandlers(): array
     {
+        if (is_null(dcCore::app()->blog)) {
+            return [];
+        }
         $handlers = json_decode((string) dcCore::app()->blog->settings->get(My::id())->get(My::NS_SETTING_ID), true);
 
         return is_array($handlers) ? $handlers : [];
     }
 
+    /**
+     * Save custom URLs handlers
+     *
+     * @param   array   $handlers   The custom URLs handlers
+     */
     public static function saveBlogHandlers(array $handlers): void
     {
+        if (is_null(dcCore::app()->blog)) {
+            return;
+        }
         dcCore::app()->blog->settings->get(My::id())->put(My::NS_SETTING_ID, json_encode($handlers));
         dcCore::app()->blog->triggerBlog();
     }