Webserver Overrides
Why?
For a very long time FreePBX has insisted that end users protect their FreePBX web directories from "directory sniffing". To help users out FreePBX has always placed an .htaccess file in the root directory of the admin folder to protect vital assets from being read such as configuration files and php scripts. However, eventhough this script was in place it did not always mean said user's system was "listening" to it. Starting in FreePBX 12 we attempt to make sure that your system is "listening" to our directives. If we detect that your server isn't listening you are redirected to this page. You need to set AllowOverride to All in your http.conf file for security reasons otherwise you are leaving your system exposed. This is covered exhaustively on the internet, google 'allow overrides apache'.
Below we have provided some quick how-to guides that should get you on the right track.
CentOS/Fedora/Red Hat
Open httpd.conf in your favorite text editor (normally in /etc/httpd/conf/httpd.conf)
Look for the context "<Directory "/var/www/html">"
Within that context make sure "AllowOverride" is uncommented and set to "All"
Restart Apache by running
service httpd restart
Ubuntu
Open apache2.conf in your favorite text editor (normally in /etc/apache2/apache2.conf)
Look for the context "<Directory "/var/www/html">" or "<Directory "/var/www">"
Within that context make sure "AllowOverride" is uncommented and set to "All"
Restart Apache by running
service apache2 restart