Unable to load type 'NHibernate.ByteCode.Castle.ProxyFactoryFactory, NHibernate.ByteCode.Castle' during configuration of proxy factory class. Possible causes are: - The NHibernate.Bytecode provider assembly was not deployed. - The typeName used to initialize the 'proxyfactory.factory_class' property of the session-factory section is not well formed. Solution: Confirm that your deployment folder contains one of the following assemblies: NHibernate.ByteCode.LinFu.dll NHibernate.ByteCode.Castle.dll
Well after hours of searching I finally found that if I changed my target build from x86 to x64 the problem resolves itself. This has to go into my top 10 most annoying bugs of all time.