Installing a PHP forum on VPS with CentOS 7

Installing a PHP forum on VPS with CentOS 7
I am new to VPS and am having problems setting up my WoltLab blog. Setting it up on shared hosting is straightforward.
But, on VPS when I enter this URL in my browser http://www.somesite/forum/install.php
I get the error message below. I don't know why as the folder is in place, and the install files are in that folder.

This is the error message that I am getting when I try to install my WoltLab blog.
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@somesite.com to inform them of the time this error occurred, and the actions you performed just before this error. More information about this error may be available in the server error log.

I have looked for this server error log, but where do I look ?

Hi,

is your server running CWP?

Yes, it is.