Parse Error - Cannot modify header information

I have no idea what is going on with this, I have checked for whitespace, but it was working fine yesterday. I think it may be the permissions on the files maybe? Any ideas would be helpful, as I am out.

thanks for any help!

Site is http://www.techprepnwo.org/index.php?id=22

« MODx Parse Error »
MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
PHP error debug
Error:
Cannot modify header information - headers already sent by (output started at /var/www/virtual/techprep/techprepnwo.org/manager/includes/document.parser.class.inc.php:519)
Error type/ Nr.:
Warning - 2
File:
/var/www/virtual/techprep/techprepnwo.org/index.php
Line:
194
Line 194 source:
header('P3P: CP="NOI NID ADMa OUR IND UNI COM NAV"'); // header for weird cookie stuff. Blame IE.
Parser timing
MySQL:
0.0003 s
(0 Requests)
PHP:
0.0165 s
Total:
0.0168 s

Hello,

What version of MODX and what version of PHP are you using?

It could be a plugin or snippet throwing an error and calling exit() or die().

Thanks for the help, but one of my co-workers is a php guy and found that modx had a bunch of trojan php files which pasted in code into the index.php files creating two copies of the code. We removed that code and scanned the FS and found 53 trojans in 5 of the sites.

Not sure which version of modx.
CentOS 6

Thanks again.

The fact you have found and removed malicious files from the server points to having an older MODX Evolution site, and one of the recent exploits was likely used to compromise it.

I would strongly recommend a clean upgrade of MODX to the latest version (Evo 1.0.8 or Revo 2.2.6), and also confirm your php version.