每次我运行命令composerinstall--no dev时，我都会遇到这个错误，正如错误指出的那样，我正在使用laravel中的maatwebsite，我只是不知道如何修复它。

PHP致命错误：未捕获的Symfony\组件\调试\异常\FatalThrowableError
：类'PHPExcel_Shared_Font'未在 /var/www/laravel/config/excel.php:18
2堆栈跟踪：

/加载配置。php（60）：require（）

/LoadConfiguration.php（38）：照明\基金会\引导\负载配置-

在…上php（203）：Illumb\Foundation\Bootstrap\LoadConfiguration-

ernel.php（268）：照明\基础\应用-

欧尼尔。php（114）：照亮\基础\控制台\内核-

更新：这是作曲家。json文件内容

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": ">=5.6.4",
        "laravel/framework": "5.3.*"
    },
    "require-dev": {
        "fzaninotto/faker": "~1.4",
        "mockery/mockery": "0.9.*",
        "phpunit/phpunit": "~5.0",
        "symfony/css-selector": "3.1.*",
        "symfony/dom-crawler": "3.1.*",
        "maatwebsite/excel": "~2.1.0"
    },
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App\\": "app/"
        }
    },
    "autoload-dev": {
        "classmap": [
            "tests/TestCase.php"
        ]
    },
    "scripts": {
        "post-root-package-install": [
            "php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "php artisan key:generate"
        ],
        "post-install-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postInstall",
            "php artisan optimize"
        ],
        "post-update-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postUpdate",
            "php artisan optimize"
        ]
    },
    "config": {
        "preferred-install": "dist"
    }
}