Fatal Error when trying to log in DRUPAL My Drupal 7 website is throwing 500 internal server error, when I try to log in as Admin.

I checked the apache error log it throws below error

 PHP Fatal error:  require_once(): Failed opening required '/*****/******/sites/all/modules/context/context_ui/export_ui/context.inc' (include_path='.:/usr/share/pear:/usr/share/php') in /******/******/sites/all/modules/ctools/includes/plugins.inc on line 480, referer: http://*******/user


What could be the problem ?

Thanks
Can you confirm which version of php you are using? I just realized that the magic php constant "DIR" (which I first used here in beta4) may only work in php versions 5.3 or greater, so I'm guessing you have a version that's below v5.3.

According to the Drupal requirements, the PHP requirement for Drupal 7 is "PHP 5.2.5 or higher (5.3 recommended)", So I may have made a mistake by introducing a construct that's not compatible with some php versions that Drupal 7 still supports. I'll need to fix this, but either way if you can confirm your php version that would be very helpfu