jos-Error: Application Instantiation Error

JFactory :: getApplication() @ /var/www/profile/html/index.php:31
JApplication :: getInstance() @ /var/www/profile/html/libraries/joomla/factory.php:102
JSite -> __construct() @ /var/www/profile/html/libraries/joomla/application/application.php:180
JApplication -> __construct() @ /var/www/profile/html/includes/application.php:47
JApplication -> _createSession() @ /var/www/profile/html/libraries/joomla/application/application.php:145
JApplication -> checkSession() @ /var/www/profile/html/libraries/joomla/application/application.php:1046
JDatabaseMySQLi -> execute() @ /var/www/profile/html/libraries/joomla/application/application.php:1103
JError :: raiseError() @ /var/www/profile/html/libraries/joomla/database/database/mysqli.php:396
JError :: raise() @ /var/www/profile/html/libraries/joomla/error/error.php:251
JError :: throwError() @ /var/www/profile/html/libraries/joomla/error/error.php:176
call_user_func_array() @ /var/www/profile/html/libraries/joomla/error/error.php:214
JError :: handleCallback()
call_user_func() @ /var/www/profile/html/libraries/joomla/error/error.php:765
JError :: customErrorPage()
JFactory :: getApplication() @ /var/www/profile/html/libraries/joomla/error/error.php:784
JError :: raiseError() @ /var/www/profile/html/libraries/joomla/factory.php:99
JError :: raise() @ /var/www/profile/html/libraries/joomla/error/error.php:251