I have written the following simple test in trying to learn Castle Windsor\'s Fluent Interface:
using NUnit.Framework;
using Castle.Windsor;
using System.Col
The solution to this for me was not mentioned above, so I thought I would add my answer to the long tail...
I ended up having an old reference to a class (an HttpHandler) in web.config that was no longer being used (and was no longer a valid reference). For some reason it was ignored while running in Studio (or maybe I have that class still accessible within my dev setup?) and so I only got this error once I tried deploying to IIS. I searched on the assembly name in web.config, removed the unused handler reference, then this error went away and everything works great. Hope this helps someone else.