PHP5应用程序无法在PHP7实时服务器（ubuntu 16.04）中运行 -

I have a php application. Its built in php (raw php). In my local pc its running. but when I upload to live server (ubuntu 16.04) then it doesn't work.

I have installed all php dependencies in Live server ... Still the files are not working. I found some problem in live server as given below:

1. Raw PHP (5.4 version coded ) is not working
2. Class does not call from Index.php file
3. When I run exit("OK") its return OK but page not running
4. when I add a class like $doc = ClassName::getInstance(); its not running.. Returns NULL

I think I made very silly silly mistakes. Here is the live server info :

1. IP 35.160.167.129

2. info.php : http://35.160.167.129/info.php => its running

Would you please help me how do I resolve this issue. Thanks in advance