all, I am using custom config sections in my web application. I have it working as expected when accessed via the website. However, i would like to execute this via nUnit test classes. I creatred an app.config file and named it FineUnitTests.dll.config and placed it if the bin forder where the unit tests are compiled to. The config file is below. <configSections> <!--Here we specify the type we use to map the site configuration to.--> <section name="FineSiteConfiguration" type="FineBLL.SiteSection"/> </configSections> <FineSiteConfiguration DefaultConnectionStringName="FineConnection" title="This is the title for our site" AnotherValue="100"> <Config1 Father="Scott" /> </FineSiteConfiguration> I get the following error when i execute the unit test FineUnitTests.Learn.SiteSectionTest : System.TypeInitializationException : The type initializer for 'FineBLL.Application' threw an exception. ----> System.Configuration.ConfigurationErrorsException : An error occurred creating the configuration section handler for FineSiteConfiguration: Could not load type 'FineBLL.SiteSection' from assembly 'System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. (C:\KI\FineStationery\FineMid\FineUnitTests\bin\Debug\FineUnitTests.dll.config line 8) ----> System.TypeLoadException : Could not load type 'FineBLL.SiteSection' from assembly 'System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. any help would be appreciated.