BUG: Configuration Section Tags Are Not Recognized

If you add configuration section tags before the <configSections> configuration section in the Machine.config file, you may receive the following error message when you run your ASP.NET applications:

The <configSections> section in the Machine.config file defines the configuration sections that can be used for the given configuration hierarchy within an application. If you use a configuration section tag before the <configSections> section (for example, the <runtime> or <appSettings> tag), you receive the above-mentioned error message because the configuration section handler has not yet been loaded.

This problem can also occur if the configuration section does not exist or if the configuration section handler is not defined.

To work around this problem, add the configuration section tag after the <configSections> section.

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This problem does not occur when you add a configuration section tag to the Web.config application configuration file because the Machine.config file in which the handler is defined for this section has already been processed.

Steps to Reproduce the Behavior

1. Open the Machine.config file in Notepad. Machine.config is typically located in \WINNT\Microsoft.NET\Framework\<version number>\CONFIG\.
2. Move the following <appSettings> code block so that it appears before the <configSections> section:

   <appSettings>
           <add key="XML File Name" value="myxmlFileName.xml"/>
   </appSettings>
   					

3. Save your changes to Machine.config.
4. View any existing .aspx page. You receive the above-mentioned error message.
5. Move the <appSettings> code block to the end of Machine.config just before the </configuration> section, and save your changes to Machine.config.
6. View an existing .aspx page. You no longer receive the error message.

For an overview of configuration files and predefined configuration section handlers that are included with the .NET Framework, refer to the following topic in the Microsoft .NET Framework Software Development Kit (SDK) documentation: