According to the Autofac source, the exception is thrown if either a keyed resolution with the given string (from config) or a typed resolution using Type.GetType
for the given string fails.
In your case the Type.GetType
method probably returns null
because you haven't specified a Type.AssemblyQualifiedName
in the config.
Try getting typeof(MyService).AssemblyQualifiedName
and insert that into the config.