diff --git a/README.V6-Upgrade.md b/README.V6-Upgrade.md
index 533124de..2f03b876 100644
--- a/README.V6-Upgrade.md
+++ b/README.V6-Upgrade.md
@@ -44,9 +44,24 @@ $db = new CoreLibs\DB\IO(DB_CONFIG, $log);
 // login & page access check
 $login = new CoreLibs\ACL\Login($db, $log);
 ```
+* update language class
+```php
+// pre auto detect language after login
+$locale = \CoreLibs\Language\GetLocale::setLocale();
+// set lang and pass to smarty/backend
+$l10n = new \CoreLibs\Language\L10n(
+	$locale['locale'],
+	$locale['domain'],
+	$locale['path'],
+);
+```
+* smarty needs language
+```php
+$smarty = new CoreLibs\Template\SmartyExtend($l10n, $locale);
+```
 * admin backend also needs logger
 ```php
-$cms = new CoreLibs\Admin\Backend($db, $log);
+$cms = new CoreLibs\Admin\Backend($db, $log, $l10n, $locale);
 ```
 * update and `$cms` or similar calls so db is in `$cms->db->...` and log are in `$cms->log->...`
 * update all `config.*.php` files where needed
@@ -60,6 +75,12 @@ require BASE . LIB . 'autoloader.php';
 ```
 **UPDATE:**
 ```php
+// po langs [DEPRECAED: use LOCALE]
+define('LANG', 'lang' . DIRECTORY_SEPARATOR);
+// po locale file
+define('LOCALE', 'locale' . DIRECTORY_SEPARATOR);
+```
+```php
 // SSL host name
 // define('SSL_HOST', $_ENV['SSL_HOST'] ?? '');
 ```
@@ -85,6 +106,13 @@ define('CONTENT_WIDTH', '100%');
 define('BASE_NAME', preg_replace('/[^A-Za-z0-9]/', '', $_ENV['BASE_NAME'] ?? ''));
 ```
 ```php
+/************* LANGUAGE / ENCODING *******/
+// default lang + encoding
+define('DEFAULT_LOCALE', 'en_US.UTF-8');
+// default web page encoding setting
+define('DEFAULT_ENCODING', 'UTF-8');
+```
+```php
 // BAIL ON MISSING DB CONFIG:
 // we have either no db selction for this host but have db config entries
 // or we have a db selection but no db config as array or empty
@@ -104,6 +132,10 @@ if (
 }
 ```
 ```php
+// remove SITE_LANG
+define('SITE_LOCALE', $SITE_CONFIG[HOST_NAME]['site_locale'] ?? DEFAULT_LOCALE);
+define('SITE_ENCODING', $SITE_CONFIG[HOST_NAME]['site_encoding'] ?? DEFAULT_ENCODING);
+```
 ```php
 /************* GENERAL PAGE TITLE ********/
 define('G_TITLE', $_ENV['G_TITLE'] ?? '');
@@ -118,6 +150,15 @@ In the config then
 ```php
 'db_name' => $_ENV['DB_NAME.TEST'] ?? '',
 ```
+* config.host.php update
+must add site_locale (site_lang + site_encoding)
+remove site_lang
+```php
+	// lang + encoding
+	'site_locale' => 'en_US.UTF-8',
+	// site language
+	'site_encoding' => 'UTF-8',
+```
 * copy `layout/admin/javascript/edit.jq.js`
 * check other javacsript files if needed (`edit.jq.js`)
 
diff --git a/www/configs/config.host.php b/www/configs/config.host.php
index b6d00a2c..2b57ed2e 100644
--- a/www/configs/config.host.php
+++ b/www/configs/config.host.php
@@ -27,9 +27,8 @@ $__LOCAL_CONFIG = [
 	'db_host' => 'test',
 	'location' => 'test',
 	'debug_flag' => true,
-	'site_lang' => 'en_US',
-	'site_encoding' => 'UTF-8',
 	'site_locale' => 'en_US.UTF-8',
+	'site_encoding' => 'UTF-8',
 	'login_enabled' => true
 ];
 
@@ -46,11 +45,10 @@ $SITE_CONFIG = [
 		'location' => 'test',
 		// show DEBUG override
 		'debug_flag' => true,
-		// site language
-		'site_lang' => 'en_US',
-		'site_encoding' => 'UTF-8',
-		// lang + encoding
+		// site locale
 		'site_locale' => 'en_US.UTF-8',
+		// site encoding
+		'site_encoding' => 'UTF-8',
 		// enable/disable login override
 		'login_enabled' => true
 	],
diff --git a/www/configs/config.master.php b/www/configs/config.master.php
index 1f526456..898817d8 100644
--- a/www/configs/config.master.php
+++ b/www/configs/config.master.php
@@ -65,8 +65,6 @@ define('JS', 'javascript' . DIRECTORY_SEPARATOR);
 define('TABLE_ARRAYS', 'table_arrays' . DIRECTORY_SEPARATOR);
 // smarty libs path
 define('SMARTY', 'Smarty' . DIRECTORY_SEPARATOR);
-// po langs [DEPRECAED: use LOCALE]
-define('LANG', 'lang' . DIRECTORY_SEPARATOR);
 // po locale file
 define('LOCALE', 'locale' . DIRECTORY_SEPARATOR);
 // cache path
@@ -160,11 +158,10 @@ define('CACHE_ID', 'CACHE_' . BASE_NAME . '_' . SERVER_NAME_HASH);
 define('COMPILE_ID', 'COMPILE_' . BASE_NAME . '_' . SERVER_NAME_HASH);
 
 /************* LANGUAGE / ENCODING *******/
-define('DEFAULT_LANG', 'en_US');
-// default web page encoding setting
-define('DEFAULT_ENCODING', 'UTF-8');
 // default lang + encoding
 define('DEFAULT_LOCALE', 'en_US.UTF-8');
+// default web page encoding setting
+define('DEFAULT_ENCODING', 'UTF-8');
 
 /************* LOGGING *******************/
 // below two can be defined here, but they should be
@@ -262,9 +259,8 @@ $GLOBALS['DB_CONFIG'] = DB_CONFIG;
 // debug settings, site lang, etc
 define('TARGET', $SITE_CONFIG[HOST_NAME]['location'] ?? 'test');
 define('DEBUG', $SITE_CONFIG[HOST_NAME]['debug_flag'] ?? false);
-define('SITE_LANG', $SITE_CONFIG[HOST_NAME]['site_lang'] ?? DEFAULT_LANG);
-define('SITE_ENCODING', $SITE_CONFIG[HOST_NAME]['site_encoding'] ?? DEFAULT_ENCODING);
 define('SITE_LOCALE', $SITE_CONFIG[HOST_NAME]['site_locale'] ?? DEFAULT_LOCALE);
+define('SITE_ENCODING', $SITE_CONFIG[HOST_NAME]['site_encoding'] ?? DEFAULT_ENCODING);
 define('LOGIN_ENABLED', $SITE_CONFIG[HOST_NAME]['login_enabled'] ?? false);
 define('AUTH', $SITE_CONFIG[HOST_NAME]['auth'] ?? false);
 // paths
diff --git a/www/configs/config.php b/www/configs/config.php
index 62fe0cd1..ce6c3b95 100644
--- a/www/configs/config.php
+++ b/www/configs/config.php
@@ -53,9 +53,13 @@ if (!defined('DIR')) {
 // find trigger name "admin/" or "frontend/" in the getcwd() folder
 foreach (['admin', 'frontend'] as $folder) {
 	if (strstr(getcwd() ?: '', DIRECTORY_SEPARATOR . $folder)) {
-		define('CONTENT_PATH', $folder . DIRECTORY_SEPARATOR);
 		break;
 	}
 }
+// if content path is empty, fallback is default
+if (empty($folder)) {
+	$folder = 'default';
+}
+define('CONTENT_PATH', $folder . DIRECTORY_SEPARATOR);
 
 // __END__