I am getting error after uploading my Laravel project to sever

I am getting this error after uploading my laravel project to the server. I have searched this error multiple times but not get some specific answer. I am using laravel 5.5 and PHP version 7.1.

Uncaught Error: Call to undefined function Symfony\Component\VarDumper\Dumper\json_encode() in /home/cp959319p17/public_html/vendor/symfony/var-dumper/Dumper/HtmlDumper.php:131

via Chebli Mohamed