Maybe someone knows how I can correct this so I began playing around with Symfony. Upon attempting to run the bin/vendors executable I am greeted with the below error. Any ideas?

Code:
HEAD is now at f6ec47d fixed default value
PHP Fatal error:  Class 'JMS\SecurityExtraBundle\JMSSecurityExtraBundle' not found in /Users/myname/Sites/symfony/v2.0.0/htdocs/app/AppKernel.php on line 19

Fatal error: Class 'JMS\SecurityExtraBundle\JMSSecurityExtraBundle' not found in /Users/myname/Sites/symfony/v2.0.0/htdocs/app/AppKernel.php on line 19
PHP Fatal error:  Class 'JMS\SecurityExtraBundle\JMSSecurityExtraBundle' not found in /Users/myname/Sites/symfony/v2.0.0/htdocs/app/AppKernel.php on line 19

Fatal error: Class 'JMS\SecurityExtraBundle\JMSSecurityExtraBundle' not found in /Users/mynamei/Sites/symfony/v2.0.0/htdocs/app/AppKernel.php on line 19