If you are getting 444 Script or Action Blocked error then it seems to be some problem with your php script. but forst question comes to your mind is that what is securephpx?

Well, SecurePHPx is a preload checker on the PHP scripts to block malicous scripts or urls that was used to attack the PHP pages, which we designed and created ourselves on the servers.

Ti fix this you have to add domain to SecurePHPx whitelist by editing the file /usr/lib/php/php_whitelist. Just enter the domain in this file once with www & once without www.