GetType was returning null when configurationBootstrapperType.Name is not in the executing assembly. Assembly, which is a required attribute in the nancyFx config section, was not actually being used. More detail here: https://groups.google.com/forum/#!topic/nancy-web-framework/nxz9Pl4EUxE
change to string.Concat
Merge pull request #1361 from jfis/useAssemblyNameInAspNetHttpRequestHandler

Update to AspNet HttpRequestHandler to use Fully Qualified Type Name (include assembly name)