<ul><li>Fixed fatal error in platform/assets/template/1/1/header.php — removed hardcoded old server path (require_once /var/www/html/demo_youportal/...)</li><li>Created missing headers/ subdirectory under template 1/1 with header_without_session.php and header_with_session.php — Olymp social network nav bar with dynamic menu from DB</li><li>Fixed relative include paths in header.php to use dirname(__FILE__) for correct CWD-independent resolution</li><li>Fixed TPLID and SITELINKID constant redefinition warnings in index.php — added !defined() guards to prevent double-define when define_common.php runs first via spl_autoload_register</li><li>Website front-end now renders with 0 PHP warnings: header nav, menu items, and landing content all display correctly</li></ul>