Question

When I try to remove index.php
and access controller: mysite.com/admin
I keep getting Internal Server Error.
I have no idea why it doesn’t work.

.htaccess

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /code/

RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ index.php?/$1 [L]

RewriteCond %{REQUEST_URI} ^application.*
RewriteRule ^(.*)$ index.php?/$1 [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [L]
</IfModule> 

Site config

<Directory /home/mysite.com/public_html/>
Options Indexes Includes FollowSymLinks MultiViews
AllowOverride AuthConfig FileInfo
Order allow,deny
Allow from all
</Directory> 

Apache error log

[Sat Sep 08 15:24:30 2012] [error] [client 176.106.162.240] 
Request exceeded the limit of 10 internal redirects 
due to probable configuration error. Use 'LimitInternalRecursion' 
to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.

Answer 1

Change .htaccess

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /code/

RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ index.php?/$1 [L]

RewriteCond %{REQUEST_URI} ^application.*
RewriteRule ^(.*)$ index.php?/$1 [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [L]
</IfModule> 

Into this one:

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php [L,NC]

I do not believe you need anything else.