Config File Not Found Error

This post has been migrated, original date 15 Oct 2009 If you are playing about with the configuration on your web site and you see this error:

File Not Found.   at System.Configuration.TypeUtil.GetTypeWithReflectionPermission(IInternalConfigHost host, String typeString, Boolean throwOnError)
   at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.Init(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord)
   at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.InitWithRestrictedPermissions(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord)
   at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory..ctor(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord)
   at System.Configuration.RuntimeConfigurationRecord.CreateSectionFactory(FactoryRecord factoryRecord)
   at System.Configuration.BaseConfigurationRecord.FindAndEnsureFactoryRecord(String configKey, Boolean& isRootDeclaredHere)

It could relate to how you have configured you configuration sections. My problem occurred because the DLL that contained the section handler was in a DLL I had added to the GAC, however my configuration section looked like this:

</section>
<section name="castle" type="Castle.Windsor.Configuration.AppDomain.CastleSectionHandler, Castle.Windsor"></section>

I was missing the version, culture and public key so it couldn't find the Castle.Windsor DLL in the GAC. It should have looked like this

<section name="castle" type="Castle.Windsor.Configuration.AppDomain.CastleSectionHandler, Castle.Windsor,Version=1.0.3.0, Culture=neutral, PublicKeyToken=407dd0808d44fbdc">

</section>