Solution to the ambiguous "Configuration Error" - An error occurred loading a configuration file: Object reference not set to an instance of an object.

If you see this error message it means that you have not selected a .NET framework version to use for the website or virtual directory.

To resolve, go to IIS, properties of the site, ASP.NET tab and select the .NET framework version.

Configuration Error
Description: **An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: An error occurred loading a configuration file: Object reference not set to an instance of an object.
Source Error:
[No relevant source lines]
Source File: C:\WINNT\Microsoft.NET\Framework\v2.0.50727\Config\machine.config Line: 0
**
Version Information:** Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.62