You cannot choose a top level folder .

您不能选择 顶级 目录。

The create top level public folder permission for the everyone group within security tab of the public folders object in exchange system manager has been set with an explicit deny .

在exchange系统管理器中，“公用文件夹”对象的“安全”选项卡内每个组的“创建 顶级公用 文件夹”权限已设置为明确拒绝。