I've set up a Centos 6 + CPanel 11 VPS, and everything is as it was out of the box. I've installed Phorum 5.2.20 in the public_html directory, but Phorum is causing an error 500. The error log reports:
[Mon Jul 27 11:21:57.770447 2015] [core:error] [pid 14342] [client x.x.x.x:42531] End of script output before headers: admin.php
The code works fine on my Debian LAMP server (and several other non-Centos/CPanel LAMP stacks I've used to test this), and Wordpress and some other stuff runs fine on the CentOS machine.
I've tried other code too, and it works on my other servers, but doesn't work on CentOS. Phorum is the only code that matters, so I made question focuses on that. I'm also reluctant to edit the core files of Phorum.
Any ideas?