Because security issue related to php-fpm in php 5.3/5.4, php-fpm config need modified/adjustment.
In every php-fpm pool, must exists 'listen.owner', 'listen.group' and 'listen.mode' parameters. Without this parameters, we will see 'error 500' in website and panel.
To fix this issue, follow this steps:
yum clean all
## update Kloxo-MR and also others
yum update
## only for Kloxo-MR 6.5.1.b
sh /script/php53s-installer
## importance if using mariadb instead mysql
sh /script/php54s-installer
sh /script/fixlxphpexe php54s
## run cleanup
sh /script/cleanup
## to make sure php-fpm running well
killall -9 php-fpm
sh /script/restart
sh /script/restart-web
If using phpXYm series (aka 'multiple php'), reinstall via 'webserver configure'. The same way via ssh with 'sh /script/php53m-installer' (example for php53m).