500 Internal Server Error

file_get_contents(http://api.metabolomexchange.org/datasets): failed to open stream: HTTP request failed! HTTP/1.1 500 Internal Server Error (2)

#0 [internal function]: flight\Engine->handleError(2, 'file_get_conten...', '/var/www/vhosts...', 24, Array)
#1 /var/www/vhosts/metabolomexchange.org/httpdocs/index.php(24): file_get_contents('http://api.meta...')
#2 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(160): {closure}()
#3 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(143): flight\core\Dispatcher::callFunction(Object(Closure), Array)
#4 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/Engine.php(312): flight\core\Dispatcher::execute(Object(Closure), Array)
#5 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(191): flight\Engine->_start()
#6 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(142): flight\core\Dispatcher::invokeMethod(Array, Array)
#7 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(48): flight\core\Dispatcher::execute(Array, Array)
#8 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/Engine.php(64): flight\core\Dispatcher->run('start', Array)
#9 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(191): flight\Engine->__call('start', Array)
#10 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/core/Dispatcher.php(191): flight\Engine->start()
#11 /var/www/vhosts/metabolomexchange.org/httpdocs/src/flight/Flight.php(65): flight\core\Dispatcher::invokeMethod(Array, Array)
#12 /var/www/vhosts/metabolomexchange.org/httpdocs/index.php(92): Flight::__callStatic('start', Array)
#13 /var/www/vhosts/metabolomexchange.org/httpdocs/index.php(92): Flight::start()
#14 {main}