FYI - I ran into this error on the installation. I had SELinux disabled. I reverted my snapshot back and enabled SELinux and reran the script and it completed. This is on a CentOS 5.7 64 bit VM on ESXi 4.1.
Running './8-selinux'...
setenforce: SELinux is disabled
RESULT=1
===================
INSTALLATION ERROR!
===================
Installation step failed - exiting.
Check for error messages in the install log (install.log).
If you require assistance in resolving the issue, please include install.log
in your communications with Nagios Fusion technical support.
The script that failed was: './8-selinux'