无法在Django中加载模板

Question

这是我的设置：

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                # Insert your TEMPLATE_CONTEXT_PROCESSORS here or use this
                # list if you haven't customized them:
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
                "django.core.context_processors.debug",
                "django.core.context_processors.i18n",
                "django.core.context_processors.static",
                "django.core.context_processors.media",
                "django.core.context_processors.request",
                "django.core.context_processors.tz",
                "mezzanine.conf.context_processors.settings",
                "mezzanine.pages.context_processors.page",
                "main.context_processors.global_settings",
            ],
            "builtins": [
                "mezzanine.template.loader_tags",
            ],
        },
    },
]

我有结构：

project_name
- theme_1
- theme_2
- templates
-- theme_1
--- index.html
--- base.html
-- theme_2
--- index.html
--- base.html
- static
- project_name

我还尝试在应用/主题中添加结构：

theme_1
- templates
-- theme_1
--- base.html
theme_2
- templates
-- theme_2
--- base.html

这可能是什么问题？为什么我的模板文件没有加载？我只获得要加载的默认Mezzanine项目模板和静态文件。