Class 'Symfony\Component\HttpFoundation\ParameterBag' not found

I'm getting the following error when I try to run php artisan on a clean install of Laravel 5.1.43 on a Vagrant box. I've listed the versions below.

PHP Fatal error:  Class 'Symfony\Component\HttpFoundation\ParameterBag' not found in /var/www/vendor/symfony/http-foundation/Request.php on line 240
PHP Stack trace:
PHP   1. {main}() /var/www/artisan:0
PHP   2. Illuminate\Foundation\Console\Kernel->handle() /var/www/artisan:36
PHP   3. Illuminate\Foundation\Console\Kernel->bootstrap() /var/www/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php:105
PHP   4. Illuminate\Foundation\Application->bootstrapWith() /var/www/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php:208
PHP   5. Illuminate\Foundation\Bootstrap\SetRequestForConsole->bootstrap() /var/www/vendor/laravel/framework/src/Illuminate/Foundation/Application.php:203
PHP   6. Symfony\Component\HttpFoundation\Request::create() /var/www/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/SetRequestForConsole.php:20
PHP   7. Symfony\Component\HttpFoundation\Request::createRequestFromFactory() /var/www/vendor/symfony/http-foundation/Request.php:398
PHP   8. Symfony\Component\HttpFoundation\Request->__construct() /var/www/vendor/symfony/http-foundation/Request.php:1943
PHP   9. Symfony\Component\HttpFoundation\Request->initialize() /var/www/vendor/symfony/http-foundation/Request.php:222


  [Symfony\Component\Debug\Exception\FatalErrorException]
  Class 'Symfony\Component\HttpFoundation\ParameterBag' not found

Host machine:

• macOS 10.13 17A365
• Vagrant 2.0.0
• Composer 1.5.2 2017-09-11 16:59:25

Vagrant box:

• Ubuntu 14.04.5 LTS (GNU/Linux 3.13.0-132-generic x86_64)
• PHP 5.6.31-6+ubuntu14.04.1+deb.sury.org+1 (cli) with Xdebug v2.5.5

If it is helpful, I can upload my Vagrantfile and install.sh files, and also my composer.json file.

via Chebli Mohamed