symfony: Webprofiler "Argument 2 passed to Symfony\Bundle\WebProfilerBundle\Twig\WebProfilerExtension::dumpData()" error

Q	A
Bug report?	yes
Feature request?	no
BC Break report?	yes
RFC?	no
Symfony version	4.0.0-BETA2

Using Symfony Flex with version 4.0.0-BETA2 with the composer.json below, when logging in or as anonymous and trying to access the doctrine section or security section of the web profiler returns the following error for both (all other sections are fine)

Type error: Argument 2 passed to Symfony\Bundle\WebProfilerBundle\Twig\WebProfilerExtension::dumpData() must be an instance of Symfony\Component\VarDumper\Cloner\Data, null given, called in /beta2/var/cache/dev/twig/01/0179a685ace86281d0a70ef66f92ed078b595a533f89935addc2d2832b7b3795.php on line 749

Type error: Argument 2 passed to Symfony\Bundle\WebProfilerBundle\Twig\WebProfilerExtension::dumpData() must be an instance of Symfony\Component\VarDumper\Cloner\Data, array given, called in /beta2/var/cache/dev/twig/48/48b45b978a28ff1cde1082d35a927d1cd986704029abdd25b28918c42e0516fe.php on line 630

Composer.json

{
    "type": "project",
    "license": "proprietary",
    "minimum-stability": "beta",
    "require": {
        "php": "^7.1.8",
        "sensio/framework-extra-bundle": "^5.0",
        "symfony/asset": "^4.0@beta",
        "symfony/console": "^4.0",
        "symfony/expression-language": "^4.0@beta",
        "symfony/flex": "^1.0",
        "symfony/form": "^4.0@beta",
        "symfony/framework-bundle": "^4.0",
        "symfony/lts": "^4@dev",
        "symfony/monolog-bundle": "^3.1",
        "symfony/orm-pack": "^1.0",
        "symfony/requirements-checker": "^1.0",
        "symfony/security-bundle": "^4.0@beta",
        "symfony/swiftmailer-bundle": "^3.1",
        "symfony/translation": "^4.0@beta",
        "symfony/twig-bundle": "^4.0@beta",
        "symfony/validator": "^4.0@beta",
        "symfony/yaml": "^4.0",
        "twig/extensions": "^1.5"
    },
    "require-dev": {
        "symfony/debug-bundle": "^4.0@beta",
        "symfony/dotenv": "^4.0",
        "symfony/profiler-pack": "^1.0",
        "symfony/var-dumper": "^4.0@beta"
    },
    "config": {
        "preferred-install": {
            "*": "dist"
        },
        "sort-packages": true
    },
    "autoload": {
        "psr-4": {
            "App\\": "src/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "App\\Tests\\": "tests/"
        }
    },
    "scripts": {
        "auto-scripts": {
            "cache:clear": "symfony-cmd",
            "assets:install --symlink --relative %PUBLIC_DIR%": "symfony-cmd",
            "requirements-checker": "script"
        },
        "post-install-cmd": [
            "@auto-scripts"
        ],
        "post-update-cmd": [
            "@auto-scripts"
        ]
    },
    "conflict": {
        "symfony/symfony": "*"
    },
    "extra": {
        "symfony": {
            "id": "01BWT9DKN35141YD3CV7D3FD34",
            "allow-contrib": false
        }
    }
}