What can i do for this error?

内部服务器错误
服务器不能完成你的请求。

如果再次发生,请在下方将技术详情发送给服务器管理员。

更多细节可以在服务器日志中找到.

技术细节
远程地址: 192.168.31.181
请求 ID: njNj4363bfLTynfBXbr9

Xbr9",“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:"–",“app”:“PHP”,“method”:“GET”,“url”:"/…
2018/02/26 13:06:53 [error] 13521#13521: *158 FastCGI sent in stderr: “PHP message: PHP Warning: fileperms(): stat failed for /srv/dev-disk-by-label-wd1/nc/nextcloud/data/…
PHP message: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:”–",“app”:“index”,“method”:“GET”,“url”:"\…
2018/02/26 13:06:53 [error] 13521#13521: *158 FastCGI sent in stderr: “sage: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“1…
PHP message: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:”–”,“app”:“PHP”,“method”:“GET”,“url”:"/…
PHP message: PHP Warning: fileperms(): stat failed for /srv/dev-disk-by-label-wd1/nc/nextcloud/data/nextcloud.log in /srv/dev-disk-by-label-wd1/nc/nextcloud/lib/private/Log…
PHP message: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:"–",“app”:“PHP”,“method”:“GET”,“url”:"/…
PHP message: PHP Warning: fileperms(): stat failed for /srv/dev-disk-by-label-wd1/nc/nextcloud/data/nextcloud.log in /srv/dev-disk-by-label-wd1/nc/nextcloud/lib/private/Log…
PHP message: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-02-26T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:"–",“app”:“PHP”,“method”:“GET”,“url”:"/…
日志 
n… 消息
PHP message: {“reqId”:“njNj4363bfLTynfBXbr9”,“level”:3,“time”:“2018-0226T18:06:53+00:00”,“remoteAddr”:“192.168.31.181”,“user”:"-",“app”:“PHP”,“method”:“GET”,“url”:"/nextcloud/index.php",“message”:“chmod(): No such file or directory at /srv/dev-disk-by-labelwd1/nc/nextcloud/lib/private/Log/File.php#137”,“userAgent”:“Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36”,“version”:""}" while reading upstream, client: 192.168.31.181, server: , request: “GET /nextcloud/index.php HTTP/1.1”, upstream: “fastcgi://unix:/var/run/fpm-256cac39-9f644c3e-8bd0-33bdfdb7ce46.sock:”, host: “192.168.31.166:88”, referrer: “http://192.168.31.166:88/nextcloud/