当我在我的Symfony 4应用程序中启用“dev”模式时（已经在共享主机服务中在线），它显示以下消息：

(1/1) ParameterNotFoundException
You have requested a non-existent parameter "locale".

in ParameterBag.php (line 100)
at ParameterBag->get('locale')
in EnvPlaceholderParameterBag.php (line 57)
at EnvPlaceholderParameterBag->get('locale')
in ParameterBag.php (line 216)
at ParameterBag->resolveString('%locale%', array('locale' => true))
in ParameterBag.php (line 187)
...

并且不允许调试应用程序。我的config/services.yml代码是默认的：

# Put parameters here that don't need to change on each machine where the app is deployed
# https://symfony.com/doc/current/best_practices/configuration.html#application-related-configuration
parameters:
    locale: 'en'

services:
    # default configuration for Services in *this* file
    _defaults:
        autowire: true      # Automatically injects dependencies in your Services.
        autoconfigure: true # Automatically registers your Services as commands, event subscribers, etc.
        public: false       # Allows optimizing the container by removing unused Services; this also means
                            # fetching Services directly from the container via $container->get() won't work.
                            # The best practice is to be explicit about your dependencies anyway.
...

有人可以帮助我修复此错误。