title: Codeigniter 500 internal server error when using controller
body: <p>I have a site that until a few days ago was working perfectly. It's setup in different sub domains, etching using codeigniter. The main website is fine and working well, however the admin us domain has all of a sudden begun to display 500 errors when I login. 
  I can access the different areas of it by typing the address eg
  </p>
  
  <p>However when I return to the main page <a href="http://admin.mysite.com" rel="nofollow">http://admin.mysite.com</a> it kicks out a 500 error.</p>
  
  <p>In the same way when I try to submit an article to be published on the site the same 500 error occurs. It seems that whenever I need to use a controller it generates a 500 error. </p>
  
  <p>I don't think it's the htaccess, it hasn't changed at all (indeed I've tried to restore the whole domain from backups) and the 500 error persists.</p>
  
  <p>I've toyed with the idea of an apache problem but mod_rewrite is set, indeed as the site on the main domain is still functioning this makes it even more puzzling. </p>
  
  <p>Can anyone push me in the right direction. As ever with these things I hope I'm asking the right questions. I have been trying to fix this for two days straight and I'm at a loss!</p>
  
  <p>EDIT: I have managed to produce an error finally:</p>
  
  <blockquote>
    <p>Fatal error: Uncaught exception 'Exception' with message 'GAPI: Failed
    to request report data. Error: "GDatainsufficientPermissionsUser does
    not have sufficient permissions for this profile."' in
    /var/www/vhosts/dealersupport.co.uk/admin/application/third_party/analytics/gapi.class.php:218
    Stack trace: #0
    /var/www/vhosts/dealersupport.co.uk/admin/application/modules/analytics/libraries/analytics_lib.php(86):
    gapi->requestReportData('20924509', Array, Array, Array, NULL,
    '2011-12-23', '2012-11-23') #1
    /var/www/vhosts/dealersupport.co.uk/admin/application/controllers/home.php(34):
    Analytics_lib->get() #2 [internal function]: Home->index() #3
    /var/www/vhosts/dealersupport.co.uk/admin/system/core/CodeIgniter.php(359):
    call_user_func_array(Array, Array) #4
    /var/www/vhosts/dealersupport.co.uk/admin/index.php(202):
    require_once('/var/www/vhosts...') #5 {main} thrown in
    /var/www/vhosts/dealersupport.co.uk/admin/application/third_party/analytics/gapi.class.php
    on line 218</p>
  </blockquote>
  
  <p>EDIT 2: And this:</p>
  
  <blockquote>
    <p>Fatal error: Cannot access protected property MY_Form_validation::$CI
    in
    /var/www/vhosts/dealersupport.co.uk/admin/application/modules/news/controllers/news.php
    on line 459</p>
  </blockquote>
  
  <p>EDIT3: and for the sake of completeness here is the htaccess</p>
  
  <blockquote>
    <p>Options +FollowSymLinks +SymLinksIfOwnerMatch RewriteEngine On</p>
    
    <p>Options -MultiViews</p>
    
    <h1>Prevent access via browsers to all htaccess files.     order allow,deny    deny from all </h1>
    
    <p>
        RewriteEngine On</p>
    
    <p># Shortcut globally accessible design locations, to hide true
    location  # of these files from users.    RewriteRule
    ^(css|js|images)/(.*)$ application/assets/$1/$2 [L]   RewriteRule
    ^modules/([a-z_]+)/(css|js|images)/(.*)$
    application/modules/$1/assets/$2/$3 [L]</p>
  
  <pre><code># Checks to see if the user is attempting to access a valid file,
  # such as an image or css document, if this isn't true it sends the
  # request to index.php
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule ^(.*)$ index.php?/$1 [L] &lt;/IfModule&gt;
  </code></pre>
    
    <p>
        # If we don't have mod_rewrite installed, all 404's
        # can be sent to index.php, and everything works as normal.
        # Submitted by: ElliotHaughin</p>
  
  <pre><code>ErrorDocument 404 /index.php &lt;/IfModule&gt;
  </code></pre>
    
    <p>  # Turn off ETags, to improve performance.<br>
      Header unset ETag   FileETag None </p>
    
    <h1>Prevent directory listing. Options -Indexes</h1>
  </blockquote>