diff --git a/admin/admin_cron.php b/admin/admin_cron.php
index 74d8bd24a..65bab3b8a 100644
--- a/admin/admin_cron.php
+++ b/admin/admin_cron.php
@@ -79,7 +79,7 @@ switch ($mode) {
         ));
 
         //detect cron status
-        if (file_exists(CRON_RUNNING)) {
+        if (is_file(CRON_RUNNING)) {
             $template->assign_vars(array(
                 'CRON_RUNNING' => true,
             ));
@@ -87,7 +87,7 @@ switch ($mode) {
         break;
 
     case 'repair':
-        if (file_exists(CRON_RUNNING)) {
+        if (is_file(CRON_RUNNING)) {
             rename(CRON_RUNNING, CRON_ALLOWED);
         }
         redirect('admin/' . basename(__FILE__) . '?mode=list');
diff --git a/admin/admin_sitemap.php b/admin/admin_sitemap.php
index 4da8d36a3..8aef3b309 100644
--- a/admin/admin_sitemap.php
+++ b/admin/admin_sitemap.php
@@ -40,7 +40,7 @@ if (!$result = DB()->sql_query($sql)) {
 }
 
 $s_mess = $lang['SITEMAP_CREATED'] . ': <b>' . bb_date($new['sitemap_time'], $bb_cfg['post_date_format']) . '</b> ' . $lang['SITEMAP_AVAILABLE'] . ': <a href="' . make_url('sitemap/sitemap.xml') . '" target="_blank">' . make_url('sitemap/sitemap.xml') . '</a>';
-$message = file_exists(SITEMAP_DIR . '/sitemap.xml') ? $s_mess : $lang['SITEMAP_NOT_CREATED'];
+$message = is_file(SITEMAP_DIR . '/sitemap.xml') ? $s_mess : $lang['SITEMAP_NOT_CREATED'];
 
 $template->assign_vars([
     'STATIC_SITEMAP' => $new['static_sitemap'],
diff --git a/admin/index.php b/admin/index.php
index 45a635ed0..5628bd95e 100644
--- a/admin/index.php
+++ b/admin/index.php
@@ -67,7 +67,7 @@ if (isset($_GET['pane']) && $_GET['pane'] == 'left') {
     $template->assign_vars([
         'TPL_ADMIN_MAIN' => true,
         'ADMIN_LOCK' => (bool)$bb_cfg['board_disable'],
-        'ADMIN_LOCK_CRON' => file_exists(BB_DISABLED),
+        'ADMIN_LOCK_CRON' => is_file(BB_DISABLED),
     ]);
 
     // Get forum statistics
diff --git a/common.php b/common.php
index 72cafbf27..cfd102232 100644
--- a/common.php
+++ b/common.php
@@ -49,7 +49,7 @@ if (isset($_SERVER['HTTP_CF_CONNECTING_IP'])) {
 require_once BB_PATH . '/library/defines.php';
 
 // Composer
-if (!file_exists(BB_PATH . '/vendor/autoload.php')) {
+if (!is_file(BB_PATH . '/vendor/autoload.php')) {
     die('Please <a href="https://getcomposer.org/download/" target="_blank" rel="noreferrer" style="color:#0a25bb;">install composer</a> and run <code style="background:#222;color:#00e01f;padding:2px 6px;border-radius:3px;">composer install</code>');
 }
 require_once BB_PATH . '/vendor/autoload.php';
@@ -58,10 +58,10 @@ require_once BB_PATH . '/vendor/autoload.php';
  * Gets the value of an environment variable.
  *
  * @param string $key
- * @param mixed $default
+ * @param mixed|null $default
  * @return mixed
  */
-function env(string $key, $default = null)
+function env(string $key, mixed $default = null): mixed
 {
     return \TorrentPier\Env::get($key, $default);
 }
@@ -78,7 +78,7 @@ try {
 require_once BB_PATH . '/library/config.php';
 
 // Local config
-if (file_exists(BB_PATH . '/library/config.local.php')) {
+if (is_file(BB_PATH . '/library/config.local.php')) {
     require_once BB_PATH . '/library/config.local.php';
 }
 
@@ -357,7 +357,7 @@ if (!defined('IN_TRACKER')) {
 
     if (!defined('IN_ADMIN')) {
         // Exit if tracker is disabled via ON/OFF trigger
-        if (file_exists(BB_DISABLED)) {
+        if (is_file(BB_DISABLED)) {
             dummy_exit(random_int(60, 2400));
         }
     }
diff --git a/feed.php b/feed.php
index 6409116f7..e0ec37e0b 100644
--- a/feed.php
+++ b/feed.php
@@ -34,7 +34,7 @@ if ($mode === 'get_feed_url' && ($type === 'f' || $type === 'u') && $id >= 0) {
                 bb_simple_die($lang['ATOM_ERROR'] . ' #1');
             }
         }
-        if (file_exists($bb_cfg['atom']['path'] . '/f/' . $id . '.atom') && filemtime($bb_cfg['atom']['path'] . '/f/' . $id . '.atom') > $timecheck) {
+        if (is_file($bb_cfg['atom']['path'] . '/f/' . $id . '.atom') && filemtime($bb_cfg['atom']['path'] . '/f/' . $id . '.atom') > $timecheck) {
             redirect($bb_cfg['atom']['url'] . '/f/' . $id . '.atom');
         } else {
             if (\TorrentPier\Legacy\Atom::update_forum_feed($id, $forum_data)) {
@@ -52,7 +52,7 @@ if ($mode === 'get_feed_url' && ($type === 'f' || $type === 'u') && $id >= 0) {
         if (!$username = get_username($id)) {
             bb_simple_die($lang['ATOM_ERROR'] . ' #3');
         }
-        if (file_exists($bb_cfg['atom']['path'] . '/u/' . floor($id / 5000) . '/' . ($id % 100) . '/' . $id . '.atom') && filemtime($bb_cfg['atom']['path'] . '/u/' . floor($id / 5000) . '/' . ($id % 100) . '/' . $id . '.atom') > $timecheck) {
+        if (is_file($bb_cfg['atom']['path'] . '/u/' . floor($id / 5000) . '/' . ($id % 100) . '/' . $id . '.atom') && filemtime($bb_cfg['atom']['path'] . '/u/' . floor($id / 5000) . '/' . ($id % 100) . '/' . $id . '.atom') > $timecheck) {
             redirect($bb_cfg['atom']['url'] . '/u/' . floor($id / 5000) . '/' . ($id % 100) . '/' . $id . '.atom');
         } else {
             if (\TorrentPier\Legacy\Atom::update_user_feed($id, $username)) {
diff --git a/index.php b/index.php
index e2b48e3c1..42121c302 100644
--- a/index.php
+++ b/index.php
@@ -304,7 +304,7 @@ $template->assign_vars([
     'U_SEARCH_SELF_BY_MY' => "search.php?uid={$userdata['user_id']}&amp;o=1",
     'U_SEARCH_LATEST' => 'search.php?search_id=latest',
     'U_SEARCH_UNANSWERED' => 'search.php?search_id=unanswered',
-    'U_ATOM_FEED' => file_exists($bb_cfg['atom']['path'] . '/f/0.atom') ? make_url($bb_cfg['atom']['url'] . '/f/0.atom') : false,
+    'U_ATOM_FEED' => is_file($bb_cfg['atom']['path'] . '/f/0.atom') ? make_url($bb_cfg['atom']['url'] . '/f/0.atom') : false,
 
     'SHOW_LAST_TOPIC' => $show_last_topic,
     'BOARD_START' => $bb_cfg['show_board_start_index'] ? ($lang['BOARD_STARTED'] . ':&nbsp;' . '<b>' . bb_date($bb_cfg['board_startdate']) . '</b>') : false,
@@ -395,8 +395,8 @@ if ($bb_cfg['birthday_check_day'] && $bb_cfg['birthday_enabled']) {
 
 // Allow cron
 if (IS_AM) {
-    if (file_exists(CRON_RUNNING)) {
-        if (file_exists(CRON_ALLOWED)) {
+    if (is_file(CRON_RUNNING)) {
+        if (is_file(CRON_ALLOWED)) {
             unlink(CRON_ALLOWED);
         }
         rename(CRON_RUNNING, CRON_ALLOWED);
diff --git a/info.php b/info.php
index 049b4fe14..3a66fae2a 100644
--- a/info.php
+++ b/info.php
@@ -40,7 +40,7 @@ switch ((string)$_REQUEST['show'] ?? 'not_found') {
         break;
 }
 
-$require = file_exists($htmlDir . $info['src']) ? ($htmlDir . $info['src']) : false;
+$require = is_file($htmlDir . $info['src']) ? ($htmlDir . $info['src']) : false;
 
 $template->assign_vars([
     'PAGE_TITLE' => mb_strtoupper($info['title'], 'UTF-8'),
diff --git a/library/ajax/sitemap.php b/library/ajax/sitemap.php
index 531bd2b89..b710fdc8f 100644
--- a/library/ajax/sitemap.php
+++ b/library/ajax/sitemap.php
@@ -23,7 +23,7 @@ $html = '';
 switch ($mode) {
     case 'create':
         $map->createSitemap();
-        if (file_exists(SITEMAP_DIR . '/sitemap.xml')) {
+        if (is_file(SITEMAP_DIR . '/sitemap.xml')) {
             $html .= $lang['SITEMAP_CREATED'] . ': <b>' . bb_date(TIMENOW, $bb_cfg['post_date_format']) . '</b> ' . $lang['SITEMAP_AVAILABLE'] . ': <a href="' . make_url('sitemap/sitemap.xml') . '" target="_blank">' . make_url('sitemap/sitemap.xml') . '</a>';
         } else {
             $html .= $lang['SITEMAP_NOT_CREATED'];
@@ -31,7 +31,7 @@ switch ($mode) {
         break;
 
     case 'search_update':
-        if (!file_exists(SITEMAP_DIR . '/sitemap.xml')) {
+        if (!is_file(SITEMAP_DIR . '/sitemap.xml')) {
             $map->createSitemap();
         }
 
diff --git a/library/ajax/view_torrent.php b/library/ajax/view_torrent.php
index 53625a63c..f2050d715 100644
--- a/library/ajax/view_torrent.php
+++ b/library/ajax/view_torrent.php
@@ -23,8 +23,9 @@ if (!$torrent) {
     $this->ajax_die($lang['ERROR_BUILD']);
 }
 
+$file_contents = null;
 $filename = get_attachments_dir() . '/' . $torrent['physical_filename'];
-if (!file_exists($filename) || !$file_contents = file_get_contents($filename)) {
+if (!is_file($filename) || !$file_contents = file_get_contents($filename)) {
     $this->ajax_die($lang['ERROR_NO_ATTACHMENT'] . "\n\n" . htmlCHR($filename));
 }
 
diff --git a/library/attach_mod/includes/functions_thumbs.php b/library/attach_mod/includes/functions_thumbs.php
index d22a6fb31..457ebb277 100644
--- a/library/attach_mod/includes/functions_thumbs.php
+++ b/library/attach_mod/includes/functions_thumbs.php
@@ -24,13 +24,14 @@ function createThumbnail(string $source, string $newFile, string $mimeType): boo
 {
     global $attach_config;
 
-    // Get the file information
-    $source = realpath($source);
-    $min_filesize = (int)$attach_config['img_min_thumb_filesize'];
-    $img_filesize = file_exists($source) ? filesize($source) : false;
+    // Check for source image existence
+    if (!$source = realpath($source)) {
+        return false;
+    }
 
     // Checks the max allowed filesize
-    if (!$img_filesize || $img_filesize <= $min_filesize) {
+    $min_filesize = (int)$attach_config['img_min_thumb_filesize'];
+    if (!filesize($source) || filesize($source) <= $min_filesize) {
         return false;
     }
 
@@ -48,7 +49,7 @@ function createThumbnail(string $source, string $newFile, string $mimeType): boo
     }
 
     // Check the thumbnail existence after creating
-    if (!file_exists($newFile)) {
+    if (!is_file($newFile)) {
         return false;
     }
 
diff --git a/library/config.php b/library/config.php
index 19dc11afa..d86964f78 100644
--- a/library/config.php
+++ b/library/config.php
@@ -765,7 +765,7 @@ $bb_cfg['post_img_width_decr'] = 52;
 $bb_cfg['attach_img_width_decr'] = 130;
 
 // Get default lang
-if (isset($bb_cfg['default_lang']) && file_exists(LANG_ROOT_DIR . '/' . $bb_cfg['default_lang'])) {
+if (isset($bb_cfg['default_lang']) && is_file(LANG_ROOT_DIR . '/' . $bb_cfg['default_lang'])) {
     $bb_cfg['default_lang_dir'] = LANG_ROOT_DIR . '/' . $bb_cfg['default_lang'] . '/';
 } else {
     $bb_cfg['default_lang_dir'] = LANG_ROOT_DIR . '/en/';
diff --git a/library/includes/cron/cron_run.php b/library/includes/cron/cron_run.php
index 333969ecc..b1dd95781 100644
--- a/library/includes/cron/cron_run.php
+++ b/library/includes/cron/cron_run.php
@@ -43,7 +43,7 @@ DB()->add_shutdown_query("
 foreach ($cron_jobs as $job) {
     $job_script = CRON_JOB_DIR . basename($job['cron_script']);
 
-    if (file_exists($job_script)) {
+    if (is_file($job_script)) {
         $cron_start_time = utime();
         $cron_runtime_log = '';
         $cron_write_log = (CRON_LOG_ENABLED && (CRON_FORCE_LOG || $job['log_enabled'] >= 1));
diff --git a/library/includes/cron/jobs/sitemap.php b/library/includes/cron/jobs/sitemap.php
index 5a91c2fd1..5a2c29508 100644
--- a/library/includes/cron/jobs/sitemap.php
+++ b/library/includes/cron/jobs/sitemap.php
@@ -14,7 +14,7 @@ if (!defined('BB_ROOT')) {
 $map = new TorrentPier\Sitemap();
 $map->createSitemap();
 
-if (file_exists(SITEMAP_DIR . '/sitemap.xml')) {
+if (is_file(SITEMAP_DIR . '/sitemap.xml')) {
     $map_link = make_url(hide_bb_path(SITEMAP_DIR . '/sitemap.xml'));
 
     foreach ($bb_cfg['sitemap_sending'] as $source_name => $source_link) {
diff --git a/library/includes/cron/jobs/update_forums_atom.php b/library/includes/cron/jobs/update_forums_atom.php
index bb7d72d92..13fe16a21 100644
--- a/library/includes/cron/jobs/update_forums_atom.php
+++ b/library/includes/cron/jobs/update_forums_atom.php
@@ -16,7 +16,7 @@ global $bb_cfg;
 $timecheck = TIMENOW - 600;
 $forums_data = DB()->fetch_rowset("SELECT forum_id, allow_reg_tracker, forum_name FROM " . BB_FORUMS);
 
-if (file_exists($bb_cfg['atom']['path'] . '/f/0.atom')) {
+if (is_file($bb_cfg['atom']['path'] . '/f/0.atom')) {
     if (filemtime($bb_cfg['atom']['path'] . '/f/0.atom') <= $timecheck) {
         \TorrentPier\Legacy\Atom::update_forum_feed(0, $forums_data);
     }
@@ -25,7 +25,7 @@ if (file_exists($bb_cfg['atom']['path'] . '/f/0.atom')) {
 }
 
 foreach ($forums_data as $forum_data) {
-    if (file_exists($bb_cfg['atom']['path'] . '/f/' . $forum_data['forum_id'] . '.atom')) {
+    if (is_file($bb_cfg['atom']['path'] . '/f/' . $forum_data['forum_id'] . '.atom')) {
         if (filemtime($bb_cfg['atom']['path'] . '/f/' . $forum_data['forum_id'] . '.atom') <= $timecheck) {
             \TorrentPier\Legacy\Atom::update_forum_feed($forum_data['forum_id'], $forum_data);
         }
diff --git a/library/includes/functions.php b/library/includes/functions.php
index 6dbb0acba..5c26630d3 100644
--- a/library/includes/functions.php
+++ b/library/includes/functions.php
@@ -35,7 +35,7 @@ function get_attach_path($id, $ext_id = '', $base_path = null, $first_div = 1000
 function delete_avatar($user_id, $avatar_ext_id)
 {
     $avatar_file = $avatar_ext_id ? get_avatar_path($user_id, $avatar_ext_id) : false;
-    return ($avatar_file && file_exists($avatar_file) && unlink($avatar_file));
+    return ($avatar_file && is_file($avatar_file) && unlink($avatar_file));
 }
 
 function get_tracks($type)
@@ -2001,7 +2001,7 @@ function get_avatar($user_id, $ext_id, $allow_avatar = true, $height = '', $widt
     if ($user_id == BOT_UID && $bb_cfg['avatars']['bot_avatar']) {
         $user_avatar = '<img src="' . make_url($bb_cfg['avatars']['display_path'] . $bb_cfg['avatars']['bot_avatar']) . '" alt="' . $user_id . '" ' . $height . ' ' . $width . ' />';
     } elseif ($allow_avatar && $ext_id) {
-        if (file_exists(get_avatar_path($user_id, $ext_id))) {
+        if (is_file(get_avatar_path($user_id, $ext_id))) {
             $user_avatar = '<img src="' . make_url(get_avatar_path($user_id, $ext_id, $bb_cfg['avatars']['display_path'])) . '" alt="' . $user_id . '" ' . $height . ' ' . $width . ' />';
         }
     }
diff --git a/library/includes/init_bb.php b/library/includes/init_bb.php
index 005b65671..136e11c4e 100644
--- a/library/includes/init_bb.php
+++ b/library/includes/init_bb.php
@@ -400,7 +400,7 @@ $userdata =& $user->data;
 if (
     empty($_POST) &&
     !defined('IN_ADMIN') && !defined('IN_AJAX') &&
-    !file_exists(CRON_RUNNING) &&
+    !is_file(CRON_RUNNING) &&
     (TorrentPier\Helpers\CronHelper::isEnabled() || defined('START_CRON'))
 ) {
     if (TIMENOW - $bb_cfg['cron_last_check'] > $bb_cfg['cron_check_interval']) {
@@ -443,13 +443,13 @@ if (
 /**
  * Exit if board is disabled via trigger
  */
-if (($bb_cfg['board_disable'] || file_exists(BB_DISABLED)) && !defined('IN_ADMIN') && !defined('IN_AJAX') && !defined('IN_LOGIN')) {
+if (($bb_cfg['board_disable'] || is_file(BB_DISABLED)) && !defined('IN_ADMIN') && !defined('IN_AJAX') && !defined('IN_LOGIN')) {
     http_response_code(503);
     if ($bb_cfg['board_disable']) {
         // admin lock
         send_no_cache_headers();
         bb_die('BOARD_DISABLE');
-    } elseif (file_exists(BB_DISABLED)) {
+    } elseif (is_file(BB_DISABLED)) {
         // trigger lock
         TorrentPier\Helpers\CronHelper::releaseDeadlock();
         send_no_cache_headers();
diff --git a/src/Ajax.php b/src/Ajax.php
index 7fcfc6511..f80406004 100644
--- a/src/Ajax.php
+++ b/src/Ajax.php
@@ -88,11 +88,11 @@ class Ajax
         }
 
         // Exit if board is disabled via ON/OFF trigger or by admin
-        if ($bb_cfg['board_disable'] || file_exists(BB_DISABLED)) {
+        if ($bb_cfg['board_disable'] || is_file(BB_DISABLED)) {
             if (!isset($action_params[1]) || $action_params[1] !== true) {
                 if ($bb_cfg['board_disable']) {
                     $this->ajax_die($lang['BOARD_DISABLE']);
-                } elseif (file_exists(BB_DISABLED)) {
+                } elseif (is_file(BB_DISABLED)) {
                     $this->ajax_die($lang['BOARD_DISABLE_CRON']);
                 }
             }
diff --git a/src/Emailer.php b/src/Emailer.php
index 6fbd7ef78..4e669dee0 100644
--- a/src/Emailer.php
+++ b/src/Emailer.php
@@ -94,10 +94,10 @@ class Emailer
         if (empty($this->tpl_msg[$template_lang . $template_file])) {
             $tpl_file = LANG_ROOT_DIR . '/' . $template_lang . '/email/' . $template_file . '.html';
 
-            if (!file_exists($tpl_file)) {
+            if (!is_file($tpl_file)) {
                 $tpl_file = LANG_ROOT_DIR . '/' . $bb_cfg['default_lang'] . '/email/' . $template_file . '.html';
 
-                if (!file_exists($tpl_file)) {
+                if (!is_file($tpl_file)) {
                     bb_die('Could not find email template file: ' . $template_file);
                 }
             }
diff --git a/src/Helpers/CronHelper.php b/src/Helpers/CronHelper.php
index c531cdb7b..3ee881be9 100644
--- a/src/Helpers/CronHelper.php
+++ b/src/Helpers/CronHelper.php
@@ -32,7 +32,7 @@ class CronHelper
      */
     public static function releaseDeadlock(): void
     {
-        if (file_exists(CRON_RUNNING)) {
+        if (is_file(CRON_RUNNING)) {
             if (TIMENOW - filemtime(CRON_RUNNING) > 2400) {
                 self::enableBoard();
                 self::releaseLockFile();
@@ -47,7 +47,7 @@ class CronHelper
      */
     public static function releaseLockFile(): void
     {
-        if (file_exists(CRON_RUNNING)) {
+        if (is_file(CRON_RUNNING)) {
             rename(CRON_RUNNING, CRON_ALLOWED);
         }
         self::touchLockFile(CRON_ALLOWED);
@@ -57,7 +57,6 @@ class CronHelper
      * Создание файла блокировки
      *
      * @param string $lock_file
-     *
      * @return void
      */
     public static function touchLockFile(string $lock_file): void
@@ -72,7 +71,7 @@ class CronHelper
      */
     public static function enableBoard(): void
     {
-        if (file_exists(BB_DISABLED)) {
+        if (is_file(BB_DISABLED)) {
             rename(BB_DISABLED, BB_ENABLED);
         }
     }
@@ -84,7 +83,7 @@ class CronHelper
      */
     public static function disableBoard(): void
     {
-        if (file_exists(BB_ENABLED)) {
+        if (is_file(BB_ENABLED)) {
             rename(BB_ENABLED, BB_DISABLED);
         }
     }
@@ -98,11 +97,11 @@ class CronHelper
     {
         $lock_obtained = false;
 
-        if (file_exists(CRON_ALLOWED)) {
+        if (is_file(CRON_ALLOWED)) {
             $lock_obtained = rename(CRON_ALLOWED, CRON_RUNNING);
-        } elseif (file_exists(CRON_RUNNING)) {
+        } elseif (is_file(CRON_RUNNING)) {
             self::releaseDeadlock();
-        } elseif (!file_exists(CRON_ALLOWED) && !file_exists(CRON_RUNNING)) {
+        } elseif (!is_file(CRON_ALLOWED) && !is_file(CRON_RUNNING)) {
             file_write('', CRON_ALLOWED);
             $lock_obtained = rename(CRON_ALLOWED, CRON_RUNNING);
         }
@@ -114,8 +113,9 @@ class CronHelper
      * Отслеживание запуска задач
      *
      * @param string $mode
+     * @return void
      */
-    public static function trackRunning(string $mode)
+    public static function trackRunning(string $mode): void
     {
         if (!defined('START_MARK')) {
             define('START_MARK', TRIGGERS_DIR . '/cron_started_at_' . date('Y-m-d_H-i-s') . '_by_pid_' . getmypid());
@@ -127,7 +127,7 @@ class CronHelper
                 file_write('', START_MARK);
                 break;
             case 'end':
-                if (file_exists(START_MARK)) {
+                if (is_file(START_MARK)) {
                     unlink(START_MARK);
                 }
                 break;
diff --git a/src/Helpers/IPHelper.php b/src/Helpers/IPHelper.php
index c39f346f5..47a6c3936 100644
--- a/src/Helpers/IPHelper.php
+++ b/src/Helpers/IPHelper.php
@@ -60,7 +60,6 @@ class IPHelper extends Ip
      * @param string $ip
      * @return string
      */
-
     public static function long2ip_extended(string $ip): string
     {
         return self::long2ip($ip, $ip > 0xFFFFFFFF);
diff --git a/src/Helpers/IsHelper.php b/src/Helpers/IsHelper.php
index abb8fe9eb..8368f13d4 100644
--- a/src/Helpers/IsHelper.php
+++ b/src/Helpers/IsHelper.php
@@ -30,38 +30,4 @@ class IsHelper
         }
         return $is_secure;
     }
-
-    /**
-     * Return true if $value contains numbers
-     *
-     * @param string $value
-     * @return bool
-     */
-    public static function isContainsNums(string $value): bool
-    {
-        return preg_match('@[[:digit:]]@', $value);
-    }
-
-    /**
-     * Return true if $value contains letters (Uppercase included)
-     *
-     * @param string $value
-     * @param bool $uppercase
-     * @return bool
-     */
-    public static function isContainsLetters(string $value, bool $uppercase = false): bool
-    {
-        return $uppercase ? preg_match('@[A-Z]@', $value) : preg_match('@[a-z]@', $value);
-    }
-
-    /**
-     * Return true if $value contains special symbols
-     *
-     * @param string $value
-     * @return bool
-     */
-    public static function isContainsSpecSymbols(string $value): bool
-    {
-        return preg_match('@[[:punct:]]@', $value);
-    }
 }
diff --git a/src/Helpers/StringHelper.php b/src/Helpers/StringHelper.php
new file mode 100644
index 000000000..780e66b2d
--- /dev/null
+++ b/src/Helpers/StringHelper.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * TorrentPier – Bull-powered BitTorrent tracker engine
+ *
+ * @copyright Copyright (c) 2005-2024 TorrentPier (https://torrentpier.com)
+ * @link      https://github.com/torrentpier/torrentpier for the canonical source repository
+ * @license   https://github.com/torrentpier/torrentpier/blob/master/LICENSE MIT License
+ */
+
+namespace TorrentPier\Helpers;
+
+/**
+ * Class StringHelper
+ * @package TorrentPier\Helpers
+ */
+class StringHelper
+{
+    /**
+     * Return true if $value contains numbers
+     *
+     * @param string $value
+     * @return bool
+     */
+    public static function isContainsNums(string $value): bool
+    {
+        return preg_match('@[[:digit:]]@', $value);
+    }
+
+    /**
+     * Return true if $value contains letters (Uppercase included)
+     *
+     * @param string $value
+     * @param bool $uppercase
+     * @return bool
+     */
+    public static function isContainsLetters(string $value, bool $uppercase = false): bool
+    {
+        return $uppercase ? preg_match('@[A-Z]@', $value) : preg_match('@[a-z]@', $value);
+    }
+
+    /**
+     * Return true if $value contains special symbols
+     *
+     * @param string $value
+     * @return bool
+     */
+    public static function isContainsSpecSymbols(string $value): bool
+    {
+        return preg_match('@[[:punct:]]@', $value);
+    }
+}
diff --git a/src/Legacy/Template.php b/src/Legacy/Template.php
index 1c2ad3fcd..1e08f4dd5 100644
--- a/src/Legacy/Template.php
+++ b/src/Legacy/Template.php
@@ -111,7 +111,7 @@ class Template
         $this->use_cache = $bb_cfg['xs_use_cache'];
 
         // Check template exists
-        if (!file_exists($this->root) || !is_dir($this->root)) {
+        if (!is_dir($this->root)) {
             die("Theme ({$this->tpl}) directory not found");
         }
     }
diff --git a/src/Validate.php b/src/Validate.php
index 515342d3d..95c742376 100644
--- a/src/Validate.php
+++ b/src/Validate.php
@@ -16,7 +16,7 @@ use Egulias\EmailValidator\Validation\RFCValidation;
 use Egulias\EmailValidator\Validation\MessageIDValidation;
 use Egulias\EmailValidator\Validation\Extra\SpoofCheckValidation;
 
-use TorrentPier\Helpers\IsHelper;
+use TorrentPier\Helpers\StringHelper;
 
 /**
  * Class Validate
@@ -181,24 +181,24 @@ class Validate
         if ($bb_cfg['password_symbols']) {
             // Numbers
             if ($bb_cfg['password_symbols']['nums']) {
-                if (!IsHelper::isContainsNums($password)) {
+                if (!StringHelper::isContainsNums($password)) {
                     return $lang['CHOOSE_PASS_ERR_NUM'];
                 }
             }
             // Letters
             if ($bb_cfg['password_symbols']['letters']['lowercase']) {
-                if (!IsHelper::isContainsLetters($password)) {
+                if (!StringHelper::isContainsLetters($password)) {
                     return $lang['CHOOSE_PASS_ERR_LETTER'];
                 }
             }
             if ($bb_cfg['password_symbols']['letters']['uppercase']) {
-                if (!IsHelper::isContainsLetters($password, true)) {
+                if (!StringHelper::isContainsLetters($password, true)) {
                     return $lang['CHOOSE_PASS_ERR_LETTER_UPPERCASE'];
                 }
             }
             // Spec symbols
             if ($bb_cfg['password_symbols']['spec_symbols']) {
-                if (!IsHelper::isContainsSpecSymbols($password)) {
+                if (!StringHelper::isContainsSpecSymbols($password)) {
                     return $lang['CHOOSE_PASS_ERR_SPEC_SYMBOL'];
                 }
             }