The reason of this error is a mis-configuration of your web server and its Apache settings. In order to fix this, you have to try two things, edit .htaccess and php.ini file on your Joomla root location. Here is the step by step procedure :
- Edit your .htaccess file and try to find , RewriteEngine On and RewriteBase . Remove any # before those two keywords .
- Then find this
Options +FollowSymLinksand add the below right after it,
- Edit your php.ini file in the root folder and add this to the end of the file,
cgi.fix_pathinfo = 1
- Now goto Global Configuration and enable SEF and URL Rewrite and then clear cache and test the frontend.