I have a joomla website installed and working good. i installed Qlue404 component which redirects 404 page to a custom page., sometimes when i try the symbols ' and some others the 404 page appears with the message "Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request." also it shows the server information *Apache mod_fcgid/2.3.6 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/126.96.36.19935 Server at mywebsite.com Port 80*
how can i disable this message? i swear this leads to get all information for a hacker to do an Sql Injection.