Warning: require_once(/var/www/sg-user/src/include/facebook-php-sdk/src/facebook.php): Failed to open stream: No such file or directory in /var/www/sg-user/src/class/FacebookOauthAPI.php on line 3

Fatal error: Uncaught Error: Failed opening required '/var/www/sg-user/src/include/facebook-php-sdk/src/facebook.php' (include_path='.:/usr/share/pear:/usr/share/php:/var/www/sg-user/src/lib') in /var/www/sg-user/src/class/FacebookOauthAPI.php:3
Stack trace:
#0 /var/www/sg-user/src/include/config.php(109): require()
#1 /var/www/sg-user/src/module/signup/index.php(48): myAutoloader('FacebookOauthAP...')
#2 /var/www/sg-user/src/public/index.php(67): include_once('/var/www/sg-use...')
#3 {main}
  thrown in /var/www/sg-user/src/class/FacebookOauthAPI.php on line 3