Got yet another problem. Sigh.

I can't open php files on my add-on domain will-wright.com. My main acount snootysims.com DOES open (in site-preview) which is also using an index.php.
So there must be missing something on the will-wright.com that is included in snootysims.com.
I searched a bit and it may have to do something with apache, but I can't seem to find that in the Plesk control panel.