SuluArticleBundle抛出未定义的索引：文章

I'm trying to setup the SuluArticleBundle with ElasticSearch 2.4. I'm following the documentation but I keep getting

[Symfony\Component\Debug\Exception\ContextErrorException] Notice: Undefined index: article

when running the php bin/console assets:installcommand

This is the first time I'm using ElasticSearch and the SuluArticleBundle so I'm not sure if it's an error related to my ElasticSearch setup or the bundle setup.

Any idea what the problem might be?

Edit

This is the stack trace

Exception trace: () at /Users/jaimy/projects/student-starter/vendor/sulu/article-bundle/DependencyInjection/SuluArticleExtension.php:253 Sulu\Bundle\ArticleBundle\DependencyInjection\SuluArticleExtension->appendArticlePageConfig() at /Users/jaimy/projects/student-starter/vendor/sulu/article-bundle/DependencyInjection/SuluArticleExtension.php:207 Sulu\Bundle\ArticleBundle\DependencyInjection\SuluArticleExtension->load() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Compiler/MergeExtensionConfigurationPass.php:66 Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationPass->process() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DependencyInjection/MergeExtensionConfigurationPass.php:39 Symfony\Component\HttpKernel\DependencyInjection\MergeExtensionConfigurationPass->process() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/Compiler/Compiler.php:143 Symfony\Component\DependencyInjection\Compiler\Compiler->compile() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/DependencyInjection/ContainerBuilder.php:746 Symfony\Component\DependencyInjection\ContainerBuilder->compile() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Kernel.php:576 Symfony\Component\HttpKernel\Kernel->initializeContainer() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Kernel.php:118 Symfony\Component\HttpKernel\Kernel->boot() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Bundle/FrameworkBundle/Console/Application.php:65 Symfony\Bundle\FrameworkBundle\Console\Application->doRun() at /Users/jaimy/projects/student-starter/vendor/symfony/symfony/src/Symfony/Component/Console/Application.php:125 Symfony\Component\Console\Application->run() at /Users/jaimy/projects/student-starter/bin/console.php:23 include() at /Users/jaimy/projects/student-starter/bin/console:21 Edit #2

This is my sulu_core config

# SuluCore Configuration
sulu_core:
    webspace:
        config_dir: "%kernel.root_dir%/Resources/webspaces"
    content:
        structure:
            default_type:
                snippet: "article_default"
            paths:
                homepage:
                    path: "%kernel.root_dir%/Resources/templates/pages"
                    type: "home"
                page:
                    path: "%kernel.root_dir%/Resources/templates/pages"
                    type: "page"
                snippet:
                    path: "%kernel.root_dir%/Resources/templates/snippets"
                    type: "snippet"
                article:
                    path: "%kernel.root_dir%/Resources/templates/articles"
                    type: "article"

I think you missed the default_type configuration for the article. please add the config at sulu_core.content.structure.default_type.article.