title: Getting 500 internal server error with Auth component in Cakephp 2.1.1 stable version
body: <p>My cakephp app 2.1.1 is currently running on Cent OS server and I keep getting 500 internal server error on random occasions whenever I try to log into the system using Auth component.</p>
  
  <p>I thought it was something to do with Apache httpd.conf settings so I changed to AllowOverride All from None but it keeps on happening.</p>
  
  <p>I'm not sure whether this is to do with .htaccess or something else with Cakephp.</p>
  
  <p>Is this actually a bug for Cakephp 2.1.1?</p>
  
  <p><strong>UPDATE 12/APR/2012</strong></p>
  
  <p><strong>I'm getting below errors in log:</strong></p>
  
  <pre><code>2012-04-11 16:26:27 Warning: Warning (512): _cake_model_ cache was unable to write 'default_ticketing_jobs_localgovstategovfedjobs' to Apc cache in [/home/commstrat2_web/html/ticket/lib/Cake/Cache/Cache.php, line 306]
  Trace:
  Cache::write() - CORE/Cake/Cache/Cache.php, line 306
  DataSource::_cacheDescription() - CORE/Cake/Model/Datasource/DataSource.php, line 306
  Mysql::describe() - CORE/Cake/Model/Datasource/Database/Mysql.php, line 334
  Model::schema() - CORE/Cake/Model/Model.php, line 1281
  DboSource::fields() - CORE/Cake/Model/Datasource/DboSource.php, line 2180
  DboSource::read() - CORE/Cake/Model/Datasource/DboSource.php, line 1027
  Model::find() - CORE/Cake/Model/Model.php, line 2635
  JobsLocalgovstategovfedjobsController::index() - APP/Controller/JobsLocalgovstategovfedjobsController.php, line 38
  ReflectionMethod::invokeArgs() - [internal], line ??
  Controller::invokeAction() - CORE/Cake/Controller/Controller.php, line 488
  Dispatcher::_invoke() - CORE/Cake/Routing/Dispatcher.php, line 103
  Dispatcher::dispatch() - CORE/Cake/Routing/Dispatcher.php, line 85
  [main] - APP/webroot/index.php, line 96
  
  2012-04-11 16:26:30 Warning: Warning (512): _cake_core_ cache was unable to write 'file_map' to Apc cache in [/home/commstrat2_web/html/ticket/lib/Cake/Cache/Cache.php, line 306]
  Trace:
  Cache::write() - CORE/Cake/Cache/Cache.php, line 306
  App::shutdown() - CORE/Cake/Core/App.php, line 884
  [main] - [internal], line ??
  
  2012-04-11 16:26:30 Warning: Warning (512): _cake_core_ cache was unable to write 'method_cache' to Apc cache in [/home/commstrat2_web/html/ticket/lib/Cake/Cache/Cache.php, line 306]
  Trace:
  Cache::write() - CORE/Cake/Cache/Cache.php, line 306
  DboSource::__destruct() - CORE/Cake/Model/Datasource/DboSource.php, line 3148
  [main] - [internal], line ??
  </code></pre>
  
  <p>Also when I enabled debug and try to log out below error aswell on browser:</p>
  
  <pre><code>Fatal error: Call to a member function logout() on a non-object in /home/commstrat2_web/html/ticket/app/Controller/UsersController.php on line 117
  </code></pre>
  
  <p>When I turn off debug, it's just coming with blank screen this happens only when logging in and out.</p>