Danke, so klappt es jetzt (fast):
	PHP-Code:
	
if (sha1(session_id() . (!Config::get('disableIpCheck') ? Environment::get('ip') : '') . 'BE_USER_AUTH') == Input::cookie('BE_USER_AUTH')) {
    $objUser = \BackendUser::getInstance();
    if ($objUser->authenticate() && $objUser->isAdmin) {
      echo 'admin';
    }
} 
 Gibt allerdings noch Warnungen in dieser Form:
	Code:
	Warning: mysqli::real_escape_string(): Couldn't fetch mysqli in system\modules\core\library\Contao\Database\Mysqli\Statement.php on line 51
Warning: mysqli::query(): Couldn't fetch mysqli in system\modules\core\library\Contao\Database\Mysqli\Statement.php on line 81
Warning: Contao\Database\Mysqli\Statement::get_error(): Couldn't fetch mysqli in system\modules\core\library\Contao\Database\Mysqli\Statement.php on line 92
 Und einen Fatal Error:
	Code:
	Fatal error: Uncaught Exception: Query error: (UPDATE tl_user SET session='' WHERE id='') in C:\websites\contao-3.5.17\system\modules\core\library\Contao\Database\Statement.php:295 Stack trace: #0 C:\websites\contao-3.5.17\system\modules\core\library\Contao\Database\Statement.php(264): Contao\Database\Statement->query() #1 C:\websites\contao-3.5.17\system\modules\core\classes\BackendUser.php(164): Contao\Database\Statement->execute('a:37:{s:7:"refe...', '1') #2 [internal function]: Contao\BackendUser->__destruct() #3 {main} thrown in C:\websites\contao-3.5.17\system\modules\core\library\Contao\Database\Statement.php on line 295