Laravelでartisanが動かない

Laravelで動いていたシステムでphp artisanが動かなくなってしまいました。
試したことは、.envファイルの存在確認と、開発環境がdevelopmentであること。
それから、bootstrap/cache/のリセットと権限の設定、
storage/logsのWEBサーバーからの書き込み権限確認
Gitを用いて、現在動いている本番環境と同じ環境であることを確認しました。
よろしくお願いします。

[ec2-user@ project]$ composer dump-autoload
Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover
PHP Fatal error:  Uncaught ReflectionException: Class config does not exist in /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php:767
Stack trace:
#0 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php(767): ReflectionClass->__construct('config')
#1 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php(646): Illuminate\Container\Container->build('config')
#2 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php(601): Illuminate\Container\Container->resolve('config', Array)
#3 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(734): Illuminate\Container\Container->make('config', Array)
#4 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php(1210): Illuminate\Foundation\Application->make('config')
#5 /var/www/html/project/vendor/laravel/framework/src/Illuminate/Support/ServiceProvider.php(57): Illuminate\Container\ in /var/www/html/project/vendor/laravel/framework/src/Illuminate/Container/Container.php on line 767
Script @php artisan package:discover handling the post-autoload-dump event returned with error code 255


{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": "^7.1.3",
        "aws/aws-sdk-php-laravel": "~3.0",
        "barryvdh/laravel-dompdf": "^0.8.3",
        "doctrine/dbal": "^2.7",
        "fideloper/proxy": "^4.0",
        "laravel/framework": "5.6.*",
        "laravel/passport": "^6.0",
        "laravel/socialite": "^3.0",
        "laravel/tinker": "^1.0",
        "laravelcollective/html": "^5.4.0",
        "league/flysystem-aws-s3-v3": "~1.0",
        "myclabs/php-enum": "^1.6",
        "simplesoftwareio/simple-qrcode": "~2",
        "kylekatarnls/laravel-carbon-2": "^1.0.0",
        "nesbot/carbon": "2.0.0-beta.2 as 1.25.0"
    },
    "require-dev": {
        "barryvdh/laravel-debugbar": "^3.2",
        "filp/whoops": "^2.0",
        "fzaninotto/faker": "^1.4",
        "laravel/dusk": "^4.0",
        "mockery/mockery": "^1.0",
        "nunomaduro/collision": "^2.0",
        "phpunit/phpunit": "^7.0",
        "squizlabs/php_codesniffer": "^3.3"
    },
    "autoload": {
        "classmap": [
            "database/seeds",
            "database/factories"
        ],
        "psr-4": {
            "App\": "app/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\": "tests/"
        }
    },
    "extra": {
        "laravel": {
            "dont-discover": [
            ]
        }
    },
    "scripts": {
        "post-root-package-install": [
            "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate"
        ],
        "post-autoload-dump": [
            "Illuminate\Foundation\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover"
        ],
        "phpcs": [
            "phpcs --standard=phpcs.xml --extensions=php ."
        ],
        "phpcbf": [
            "./vendor/bin/phpcbf --standard=./phpcs.xml"
        ]
    },
    "config": {
        "preferred-install": "dist",
        "sort-packages": true,
        "optimize-autoloader": true
    },
    "minimum-stability": "dev",
    "prefer-stable": true
}