Invalid object ID

#0 /var/www/metalnation.ru/app/model/Extensions/Entity.php(310): MongoId->__construct('')
#1 /var/www/metalnation.ru/app/model/Extensions/Entity.php(136): Extensions\Entity::getMongoId(NULL)
#2 /var/www/metalnation.ru/app/controllers/news/show.php(10): Extensions\Entity->populate(NULL)
#3 [internal function]: {closure}('bagiraofficial....')
#4 /var/www/metalnation.ru/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php(145): call_user_func_array(Object(Closure), Array)
#5 /var/www/metalnation.ru/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/HttpKernel.php(66): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#6 /var/www/metalnation.ru/vendor/silex/silex/src/Silex/Application.php(538): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#7 /var/www/metalnation.ru/vendor/silex/silex/src/Silex/Application.php(515): Silex\Application->handle(Object(Symfony\Component\HttpFoundation\Request))
#8 /var/www/metalnation.ru/index.php(42): Silex\Application->run()
#9 {main}