我已经建立了一个 Drupal 9 站点。它正在完美加载。我已经登录到站点，它给了我以下错误。我知道其中之一是安全更新的原因，这很好。但是第一个是不能理解的。我有更新权限并提供可写权限，但我仍然遇到同样的错误。我什至给了它一个777权限，但它仍然说它不可写。任何机构都可以帮助我解决这个问题。
FILE SYSTEM: Writable (public download method)
The directory sites/default/files is not writable. You may need to set the correct directory at the file system settings page or change the current directory's permissions so that it is writable.
PUBLIC FILES DIRECTORY: Not fully protected
See https://www.drupal.org/SA-CORE-2013-003 for information about the recommended .htaccess file which should be added to the public:// directory to help protect against arbitrary code execution.
