+1, I have also the same errors
2014/07/24 04:45:51 [emerg] 53311#0: open() "/var/www/vhosts/system/domain.com/logs/proxy_access_log" failed (13: Permission denied)
2014/07/24 04:45:51 [emerg] 53311#0: open() "/var/www/vhosts/system/domain1.com/logs/proxy_access_ssl_log" failed (13: Permission...