在WebForms app中读取自定义配置文件

I have classes to read in a custom config file, which work in my (sandbox) MVC app, and in a console app. However, it fails to read anything except the top level section when it's run from the web forms app that actually needs it. They all target framework .Net 4.5. The custom config is a 'carrier' section that contains a list of carriers, each of which has their own settings. The web.config extracts:I have classes to read in a custom config file,