500 Internal server error in wp-admin ,at update & plugins.php(Wordpress)

I'm having Internal server error in some sessions(parts) after I login in wp dashboard.

Problems are in wp-admin/plugins.php, wp-admin/plugins.php and some few other places where is relating with any plugins. I have checked .htaccess, memory limit to my server and in wp file is ok, I have deactivated all the plugins, changed themes, updated WordPress and still have the same problem.

I have check the error log and this is what it shows:

[Thu Jun 09 12:22:25 2016] [error] [client 217.73.141.38] Premature end of script headers: update-core.php, referer: http://ift.tt/1XbNrRh

[Thu Jun 09 12:22:29 2016] [warn] [client 217.73.141.38] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: http://ift.tt/1XbNrRh

[Thu Jun 09 12:22:29 2016] [error] [client 217.73.141.38] Premature end of script headers: plugins.php, referer: http://ift.tt/1XbNrRh

[Thu Jun 09 12:22:32 2016] [warn] [client 217.73.141.38] (104)Connection reset by peer: mod_fcgid: error reading data from FastCGI server, referer: http://ift.tt/1XbNrRh

via Chebli Mohamed