完成安装后，配置完域名，访问首页，后天报错
PHP message: PHP Fatal error: Class 'MongoDB\Driver\Query' not found in /var/www/html/fecshop/vendor/yiisoft/yii2-mongodb/Command.php on line 284" while reading response header from upstream, client: XX.XX.XX.XXX, server: www.XX.com, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "www.XX.com"
2017/10/23 00:39:24 [error] 22522#0: *36 open() "/var/www/html/fecshop/appfront/web/apple-touch-icon.png" failed (2: No such file or directory), client: XX.XX.XX.XXX, server: www.XX.com, request: "GET /apple-touch-icon.png HTTP/1.1", host: "www.XX.com"
MongoDB extension version => 1.3.1
"yiisoft/yii2-mongodb": "~2.1.0"
网上找的办法都试了，求助。
php-version：PHP 5.5.9-1ubuntu4.22 (cli) (built: Aug 4 2017 19:40:28)