Error In Nginx

Hi
I setup this plugin on a Apache-Php-MySql stack on windows and it was working fine. But when I port my site to LEMP (Linux, Nginx, MySQL, PHP) Stack server, Feed Reader did not update anymore ! I switched PHP version to 5.6, checking Diagnostic Mode, and Logs, but I couldn’t resolve this issue. It seems that there is a problem on the request created by plugin and Upstream in Nginx. The log contains these errors:

[error] 15258#15258: *2985 FastCGI sent in stderr: “PHP message: [********] [feedwordpress] Initiating an AUTOMATIC CHECK FOR UPDATES ON PAGE LOAD shutdown due to FeedWordPress option = string(8) “shutdown”” while reading upstream, client: ***.***.***.***, server: ********, request: “GET ******** HTTP/1.1”, upstream: “fastcgi://unix:/var/run/ajenti-v-php5.6-fcgi-php5.6-fcgi-0.sock:”, host: “********”
[error] 15258#15258: *2985 FastCGI sent in stderr: “PHP message: [********] [feedwordpress] Polling feed [********]” while reading upstream, client: ***.***.***.***, server: ********, request: “GET ******** HTTP/1.1”, upstream: “fastcgi://unix:/var/run/ajenti-v-php5.6-fcgi-php5.6-fcgi-0.sock:”, host: “********”
[error] 15258#15258: *2989 FastCGI sent in stderr: “PHP message: [********] [feedwordpress] Memory: Current usage: 21325 KB