"Twig\Loader\FilesystemLoader" not found during upgrading from 3.0.2 to 4.1.0.0

Dears, after automatic upgrading from 3.0.2 to 4.1.0.0 (PHP8.0.3) with help here, I met below error when I tried to open my store or admin:
Error: Class "Twig\Loader\FilesystemLoader" not found File: wwwroot\system\library\template\twig.php Line: 36 Backtrace: 0
File: wwwroot\system\library\template.php Line: 30 Class: Opencart\System\Library\Template\Twig Function: __construct Backtrace: 1
File: wwwroot\system\framework.php Line: 182 Class: Opencart\System\Library\Template Function: __construct Backtrace: 2
File: wwwroot\index.php Line: 20 Function: require_once

Any idea to solve it please?

dears, by the way, my "storage" folder is not system/storage, but another one folder under root(same one as in config.php), thanks

Have you updated your storage directory with the new files from 4.1.0.0? You may be better upgrading to 3.0.4.0 which is compatible with PHP 8 and more stable.